diff --git a/packages/discord.js/.eslintrc.json b/packages/discord.js/.eslintrc.json
index c76bf9863..ecfad0981 100644
--- a/packages/discord.js/.eslintrc.json
+++ b/packages/discord.js/.eslintrc.json
@@ -204,6 +204,9 @@
     {
       "files": ["typings/*.ts", "scripts/*.mjs"],
       "parser": "@typescript-eslint/parser",
+      "parserOptions": {
+        "project": "./tsconfig.json"
+      },
       "plugins": ["@typescript-eslint"],
       "rules": {
         "@typescript-eslint/naming-convention": [
@@ -216,6 +219,33 @@
               "match": true
             }
           }
+        ],
+        "no-restricted-syntax": [
+          2,
+          {
+            "selector": "MethodDefinition[key.name!=on][key.name!=once][key.name!=off] > TSEmptyBodyFunctionExpression > Identifier :not(TSTypeOperator[operator=readonly]) > TSArrayType",
+            "message": "Array parameters on methods must be readonly"
+          },
+          {
+            "selector": "MethodDefinition > TSEmptyBodyFunctionExpression > Identifier TSTypeReference > Identifier[name=Collection]",
+            "message": "Parameters of type Collection on methods must use ReadonlyCollection"
+          },
+          {
+            "selector": "TSDeclareFunction > Identifier :not(TSTypeOperator[operator=readonly]) > TSArrayType",
+            "message": "Array parameters on functions must be readonly"
+          },
+          {
+            "selector": "TSDeclareFunction Identifier TSTypeReference > Identifier[name=Collection]",
+            "message": "Parameters of type Collection on functions must use ReadonlyCollection"
+          },
+          {
+            "selector": "TSInterfaceDeclaration TSPropertySignature :not(TSTypeOperator[operator=readonly]) > TSArrayType",
+            "message": "Array properties on interfaces must be readonly"
+          },
+          {
+            "selector": "TSInterfaceDeclaration TSPropertySignature TSTypeReference > Identifier[name=Collection]",
+            "message": "Interface properties of type Collection must use ReadonlyCollection"
+          }
         ]
       }
     }
diff --git a/packages/discord.js/typings/index.d.ts b/packages/discord.js/typings/index.d.ts
index 597c16a8c..0ed374d28 100644
--- a/packages/discord.js/typings/index.d.ts
+++ b/packages/discord.js/typings/index.d.ts
@@ -305,7 +305,7 @@ export type ActionRowComponent = MessageActionRowComponent | ModalActionRowCompo
 
 export interface ActionRowData<ComponentType extends JSONEncodable<APIActionRowComponentTypes> | ActionRowComponentData>
   extends BaseComponentData {
-  components: ComponentType[];
+  components: readonly ComponentType[];
 }
 
 export class ActionRowBuilder<
@@ -395,23 +395,26 @@ export class AutoModerationRule extends Base {
   public delete(reason?: string): Promise<void>;
   public setName(name: string, reason?: string): Promise<AutoModerationRule>;
   public setEventType(eventType: AutoModerationRuleEventType, reason?: string): Promise<AutoModerationRule>;
-  public setKeywordFilter(keywordFilter: string[], reason?: string): Promise<AutoModerationRule>;
-  public setRegexPatterns(regexPatterns: string[], reason?: string): Promise<AutoModerationRule>;
-  public setPresets(presets: AutoModerationRuleKeywordPresetType[], reason?: string): Promise<AutoModerationRule>;
-  public setAllowList(allowList: string[], reason?: string): Promise<AutoModerationRule>;
+  public setKeywordFilter(keywordFilter: readonly string[], reason?: string): Promise<AutoModerationRule>;
+  public setRegexPatterns(regexPatterns: readonly string[], reason?: string): Promise<AutoModerationRule>;
+  public setPresets(
+    presets: readonly AutoModerationRuleKeywordPresetType[],
+    reason?: string,
+  ): Promise<AutoModerationRule>;
+  public setAllowList(allowList: readonly string[], reason?: string): Promise<AutoModerationRule>;
   public setMentionTotalLimit(mentionTotalLimit: number, reason?: string): Promise<AutoModerationRule>;
   public setMentionRaidProtectionEnabled(
     mentionRaidProtectionEnabled: boolean,
     reason?: string,
   ): Promise<AutoModerationRule>;
-  public setActions(actions: AutoModerationActionOptions[], reason?: string): Promise<AutoModerationRule>;
+  public setActions(actions: readonly AutoModerationActionOptions[], reason?: string): Promise<AutoModerationRule>;
   public setEnabled(enabled?: boolean, reason?: string): Promise<AutoModerationRule>;
   public setExemptRoles(
-    roles: Collection<Snowflake, Role> | RoleResolvable[],
+    roles: ReadonlyCollection<Snowflake, Role> | readonly RoleResolvable[],
     reason?: string,
   ): Promise<AutoModerationRule>;
   public setExemptChannels(
-    channels: Collection<Snowflake, GuildBasedChannel> | GuildChannelResolvable[],
+    channels: ReadonlyCollection<Snowflake, GuildBasedChannel> | readonly GuildChannelResolvable[],
     reason?: string,
   ): Promise<AutoModerationRule>;
 }
@@ -469,14 +472,19 @@ export class ApplicationCommand<PermissionsFetchType = {}> extends Base {
     defaultMemberPermissions: PermissionResolvable | null,
   ): Promise<ApplicationCommand<PermissionsFetchType>>;
   public setDMPermission(dmPermission?: boolean): Promise<ApplicationCommand<PermissionsFetchType>>;
-  public setOptions(options: ApplicationCommandOptionData[]): Promise<ApplicationCommand<PermissionsFetchType>>;
+  public setOptions(
+    options: readonly ApplicationCommandOptionData[],
+  ): Promise<ApplicationCommand<PermissionsFetchType>>;
   public equals(
     command: ApplicationCommand | ApplicationCommandData | RawApplicationCommandData,
     enforceOptionOrder?: boolean,
   ): boolean;
   public static optionsEqual(
-    existing: ApplicationCommandOption[],
-    options: ApplicationCommandOption[] | ApplicationCommandOptionData[] | APIApplicationCommandOption[],
+    existing: readonly ApplicationCommandOption[],
+    options:
+      | readonly ApplicationCommandOption[]
+      | readonly ApplicationCommandOptionData[]
+      | readonly APIApplicationCommandOption[],
     enforceOptionOrder?: boolean,
   ): boolean;
   private static _optionEquals(
@@ -862,7 +870,7 @@ export interface EmbedData {
   thumbnail?: EmbedAssetData;
   provider?: APIEmbedProvider;
   author?: EmbedAuthorData;
-  fields?: APIEmbedField[];
+  fields?: readonly APIEmbedField[];
   video?: EmbedAssetData;
 }
 
@@ -1062,7 +1070,7 @@ export class ClientApplication extends Application {
   public fetchRoleConnectionMetadataRecords(): Promise<ApplicationRoleConnectionMetadata[]>;
   public fetchSKUs(): Promise<Collection<Snowflake, SKU>>;
   public editRoleConnectionMetadataRecords(
-    records: ApplicationRoleConnectionMetadataEditOptions[],
+    records: readonly ApplicationRoleConnectionMetadataEditOptions[],
   ): Promise<ApplicationRoleConnectionMetadata[]>;
 }
 
@@ -1080,10 +1088,10 @@ export class ClientUser extends User {
   public edit(options: ClientUserEditOptions): Promise<this>;
   public setActivity(options?: ActivityOptions): ClientPresence;
   public setActivity(name: string, options?: Omit<ActivityOptions, 'name'>): ClientPresence;
-  public setAFK(afk?: boolean, shardId?: number | number[]): ClientPresence;
+  public setAFK(afk?: boolean, shardId?: number | readonly number[]): ClientPresence;
   public setAvatar(avatar: BufferResolvable | Base64Resolvable | null): Promise<this>;
   public setPresence(data: PresenceData): ClientPresence;
-  public setStatus(status: PresenceStatusData, shardId?: number | number[]): ClientPresence;
+  public setStatus(status: PresenceStatusData, shardId?: number | readonly number[]): ClientPresence;
   public setUsername(username: string): Promise<this>;
 }
 
@@ -1109,7 +1117,7 @@ export interface CollectorEventTypes<Key, Value, Extras extends unknown[] = []>
   collect: [Value, ...Extras];
   ignore: [Value, ...Extras];
   dispose: [Value, ...Extras];
-  end: [collected: Collection<Key, Value>, reason: string];
+  end: [collected: ReadonlyCollection<Key, Value>, reason: string];
 }
 
 export abstract class Collector<Key, Value, Extras extends unknown[] = []> extends EventEmitter {
@@ -1175,13 +1183,13 @@ export class AutocompleteInteraction<Cached extends CacheType = CacheType> exten
   public inGuild(): this is AutocompleteInteraction<'raw' | 'cached'>;
   public inCachedGuild(): this is AutocompleteInteraction<'cached'>;
   public inRawGuild(): this is AutocompleteInteraction<'raw'>;
-  public respond(options: ApplicationCommandOptionChoiceData[]): Promise<void>;
+  public respond(options: readonly ApplicationCommandOptionChoiceData[]): Promise<void>;
 }
 
 export class CommandInteractionOptionResolver<Cached extends CacheType = CacheType> {
   private constructor(
     client: Client<true>,
-    options: CommandInteractionOption[],
+    options: readonly CommandInteractionOption[],
     resolved: CommandInteractionResolvedData,
   );
   public readonly client: Client;
@@ -1192,14 +1200,14 @@ export class CommandInteractionOptionResolver<Cached extends CacheType = CacheTy
   private _subcommand: string | null;
   private _getTypedOption(
     name: string,
-    allowedTypes: ApplicationCommandOptionType[],
-    properties: (keyof ApplicationCommandOption)[],
+    allowedTypes: readonly ApplicationCommandOptionType[],
+    properties: readonly (keyof ApplicationCommandOption)[],
     required: true,
   ): CommandInteractionOption<Cached>;
   private _getTypedOption(
     name: string,
-    allowedTypes: ApplicationCommandOptionType[],
-    properties: (keyof ApplicationCommandOption)[],
+    allowedTypes: readonly ApplicationCommandOptionType[],
+    properties: readonly (keyof ApplicationCommandOption)[],
     required: boolean,
   ): CommandInteractionOption<Cached> | null;
 
@@ -1923,11 +1931,17 @@ export class InteractionCollector<Interaction extends CollectedInteraction> exte
   public empty(): void;
   public dispose(interaction: Interaction): Snowflake;
   public on(event: 'collect' | 'dispose' | 'ignore', listener: (interaction: Interaction) => void): this;
-  public on(event: 'end', listener: (collected: Collection<Snowflake, Interaction>, reason: string) => void): this;
+  public on(
+    event: 'end',
+    listener: (collected: ReadonlyCollection<Snowflake, Interaction>, reason: string) => void,
+  ): this;
   public on(event: string, listener: (...args: any[]) => void): this;
 
   public once(event: 'collect' | 'dispose' | 'ignore', listener: (interaction: Interaction) => void): this;
-  public once(event: 'end', listener: (collected: Collection<Snowflake, Interaction>, reason: string) => void): this;
+  public once(
+    event: 'end',
+    listener: (collected: ReadonlyCollection<Snowflake, Interaction>, reason: string) => void,
+  ): this;
   public once(event: string, listener: (...args: any[]) => void): this;
 }
 
@@ -2268,8 +2282,8 @@ export class MessageFlagsBitField extends BitField<MessageFlagsString> {
 export class MessageMentions<InGuild extends boolean = boolean> {
   private constructor(
     message: Message,
-    users: APIUser[] | Collection<Snowflake, User>,
-    roles: Snowflake[] | Collection<Snowflake, Role>,
+    users: readonly APIUser[] | ReadonlyCollection<Snowflake, User>,
+    roles: readonly Snowflake[] | ReadonlyCollection<Snowflake, Role>,
     everyone: boolean,
     repliedUser?: APIUser | User,
   );
@@ -2354,7 +2368,7 @@ export class MessageReaction {
 export interface ModalComponentData {
   customId: string;
   title: string;
-  components: (
+  components: readonly (
     | JSONEncodable<APIActionRowComponent<APIModalActionRowComponent>>
     | ActionRowData<ModalActionRowComponentData>
   )[];
@@ -2372,11 +2386,11 @@ export interface TextInputModalData extends BaseModalData {
 
 export interface ActionRowModalData {
   type: ComponentType.ActionRow;
-  components: TextInputModalData[];
+  components: readonly TextInputModalData[];
 }
 
 export class ModalSubmitFields {
-  constructor(components: ModalActionRowComponent[][]);
+  constructor(components: readonly (readonly ModalActionRowComponent[])[]);
   public components: ActionRowModalData[];
   public fields: Collection<string, ModalActionRowComponent>;
   public getField<Type extends ComponentType>(customId: string, type: Type): { type: Type } & TextInputModalData;
@@ -2502,7 +2516,7 @@ export abstract class ThreadOnlyChannel extends GuildChannel {
   public nsfw: boolean;
   public topic: string | null;
   public defaultSortOrder: SortOrderType | null;
-  public setAvailableTags(tags: GuildForumTagData[], reason?: string): Promise<this>;
+  public setAvailableTags(tags: readonly GuildForumTagData[], reason?: string): Promise<this>;
   public setDefaultReactionEmoji(emojiId: DefaultReactionEmoji | null, reason?: string): Promise<this>;
   public setDefaultThreadRateLimitPerUser(rateLimit: number, reason?: string): Promise<this>;
   public createInvite(options?: InviteCreateOptions): Promise<Invite>;
@@ -2591,7 +2605,10 @@ export class ReactionCollector extends Collector<Snowflake | string, MessageReac
     event: 'collect' | 'dispose' | 'remove' | 'ignore',
     listener: (reaction: MessageReaction, user: User) => void,
   ): this;
-  public on(event: 'end', listener: (collected: Collection<Snowflake, MessageReaction>, reason: string) => void): this;
+  public on(
+    event: 'end',
+    listener: (collected: ReadonlyCollection<Snowflake, MessageReaction>, reason: string) => void,
+  ): this;
   public on(event: string, listener: (...args: any[]) => void): this;
 
   public once(
@@ -2600,7 +2617,7 @@ export class ReactionCollector extends Collector<Snowflake | string, MessageReac
   ): this;
   public once(
     event: 'end',
-    listener: (collected: Collection<Snowflake, MessageReaction>, reason: string) => void,
+    listener: (collected: ReadonlyCollection<Snowflake, MessageReaction>, reason: string) => void,
   ): this;
   public once(event: string, listener: (...args: any[]) => void): this;
 }
@@ -2883,8 +2900,8 @@ export class ShardClientUtil {
 
 export class ShardingManager extends EventEmitter {
   public constructor(file: string, options?: ShardingManagerOptions);
-  private _performOnShards(method: string, args: unknown[]): Promise<unknown[]>;
-  private _performOnShards(method: string, args: unknown[], shard: number): Promise<unknown>;
+  private _performOnShards(method: string, args: readonly unknown[]): Promise<unknown[]>;
+  private _performOnShards(method: string, args: readonly unknown[], shard: number): Promise<unknown>;
 
   public file: string;
   public respawn: boolean;
@@ -3208,7 +3225,7 @@ export class ThreadChannel<ThreadOnly extends boolean = boolean> extends BaseCha
   public setLocked(locked?: boolean, reason?: string): Promise<AnyThreadChannel>;
   public setName(name: string, reason?: string): Promise<AnyThreadChannel>;
   // The following 3 methods can only be run on forum threads.
-  public setAppliedTags(appliedTags: Snowflake[], reason?: string): Promise<ThreadChannel<true>>;
+  public setAppliedTags(appliedTags: readonly Snowflake[], reason?: string): Promise<ThreadChannel<true>>;
   public pin(reason?: string): Promise<ThreadChannel<true>>;
   public unpin(reason?: string): Promise<ThreadChannel<true>>;
   public toString(): ChannelMention;
@@ -3324,7 +3341,7 @@ export class UserFlagsBitField extends BitField<UserFlagsString> {
 export function basename(path: string, ext?: string): string;
 export function cleanContent(str: string, channel: TextBasedChannel): string;
 export function discordSort<Key, Value extends { rawPosition: number; id: Snowflake }>(
-  collection: Collection<Key, Value>,
+  collection: ReadonlyCollection<Key, Value>,
 ): Collection<Key, Value>;
 export function cleanCodeBlockContent(text: string): string;
 export function fetchRecommendedShardCount(token: string, options?: FetchRecommendedShardCountOptions): Promise<number>;
@@ -3334,7 +3351,13 @@ export function makeError(obj: MakeErrorOptions): Error;
 /** @internal */
 export function makePlainError(err: Error): MakeErrorOptions;
 /** @internal */
-export function moveElementInArray(array: unknown[], element: unknown, newIndex: number, offset?: boolean): number;
+export function moveElementInArray(
+  // eslint-disable-next-line no-restricted-syntax
+  array: unknown[],
+  element: unknown,
+  newIndex: number,
+  offset?: boolean,
+): number;
 export function parseEmoji(text: string): PartialEmoji | null;
 export function resolveColor(color: ColorResolvable): number;
 /** @internal */
@@ -3347,7 +3370,7 @@ export function setPosition<Item extends Channel | Role>(
   item: Item,
   position: number,
   relative: boolean,
-  sorted: Collection<Snowflake, Item>,
+  sorted: ReadonlyCollection<Snowflake, Item>,
   client: Client<true>,
   route: string,
   reason?: string,
@@ -4146,7 +4169,7 @@ export class GuildApplicationCommandManager extends ApplicationCommandManager<Ap
     id?: undefined,
     options?: FetchGuildApplicationCommandFetchOptions,
   ): Promise<Collection<Snowflake, ApplicationCommand>>;
-  public set(commands: ApplicationCommandDataResolvable[]): Promise<Collection<Snowflake, ApplicationCommand>>;
+  public set(commands: readonly ApplicationCommandDataResolvable[]): Promise<Collection<Snowflake, ApplicationCommand>>;
 }
 
 export type MappedGuildChannelTypes = {
@@ -4204,11 +4227,11 @@ export class GuildEmojiRoleManager extends DataManager<Snowflake, Role, RoleReso
   public emoji: GuildEmoji;
   public guild: Guild;
   public add(
-    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | Collection<Snowflake, Role>,
+    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | ReadonlyCollection<Snowflake, Role>,
   ): Promise<GuildEmoji>;
-  public set(roles: readonly RoleResolvable[] | Collection<Snowflake, Role>): Promise<GuildEmoji>;
+  public set(roles: readonly RoleResolvable[] | ReadonlyCollection<Snowflake, Role>): Promise<GuildEmoji>;
   public remove(
-    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | Collection<Snowflake, Role>,
+    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | ReadonlyCollection<Snowflake, Role>,
   ): Promise<GuildEmoji>;
 }
 
@@ -4319,12 +4342,15 @@ export class GuildMemberRoleManager extends DataManager<Snowflake, Role, RoleRes
   public guild: Guild;
 
   public add(
-    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | Collection<Snowflake, Role>,
+    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | ReadonlyCollection<Snowflake, Role>,
+    reason?: string,
+  ): Promise<GuildMember>;
+  public set(
+    roles: readonly RoleResolvable[] | ReadonlyCollection<Snowflake, Role>,
     reason?: string,
   ): Promise<GuildMember>;
-  public set(roles: readonly RoleResolvable[] | Collection<Snowflake, Role>, reason?: string): Promise<GuildMember>;
   public remove(
-    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | Collection<Snowflake, Role>,
+    roleOrRoles: RoleResolvable | readonly RoleResolvable[] | ReadonlyCollection<Snowflake, Role>,
     reason?: string,
   ): Promise<GuildMember>;
 }
@@ -4365,7 +4391,7 @@ export class PermissionOverwriteManager extends CachedManager<
 > {
   private constructor(client: Client<true>, iterable?: Iterable<RawPermissionOverwriteData>);
   public set(
-    overwrites: readonly OverwriteResolvable[] | Collection<Snowflake, OverwriteResolvable>,
+    overwrites: readonly OverwriteResolvable[] | ReadonlyCollection<Snowflake, OverwriteResolvable>,
     reason?: string,
   ): Promise<NonThreadGuildBasedChannel>;
   private upsert(
@@ -4575,7 +4601,7 @@ export interface ActivityOptions {
 export interface AddGuildMemberOptions {
   accessToken: string;
   nick?: string;
-  roles?: Collection<Snowflake, Role> | RoleResolvable[];
+  roles?: ReadonlyCollection<Snowflake, Role> | readonly RoleResolvable[];
   mute?: boolean;
   deaf?: boolean;
   force?: boolean;
@@ -4909,10 +4935,10 @@ export interface AutoModerationActionMetadata {
 }
 
 export interface AutoModerationTriggerMetadata {
-  keywordFilter: string[];
-  regexPatterns: string[];
-  presets: AutoModerationRuleKeywordPresetType[];
-  allowList: string[];
+  keywordFilter: readonly string[];
+  regexPatterns: readonly string[];
+  presets: readonly AutoModerationRuleKeywordPresetType[];
+  allowList: readonly string[];
   mentionTotalLimit: number | null;
   mentionRaidProtectionEnabled: boolean;
 }
@@ -4929,11 +4955,11 @@ export interface AwaitModalSubmitOptions<Interaction extends ModalSubmitInteract
 }
 
 export interface AwaitMessagesOptions extends MessageCollectorOptions {
-  errors?: string[];
+  errors?: readonly string[];
 }
 
 export interface AwaitReactionsOptions extends ReactionCollectorOptions {
-  errors?: string[];
+  errors?: readonly string[];
 }
 
 export interface BanOptions {
@@ -5017,7 +5043,7 @@ export type CacheWithLimitsOptions = {
 
 export interface CategoryCreateChannelOptions {
   name: string;
-  permissionOverwrites?: OverwriteResolvable[] | Collection<Snowflake, OverwriteResolvable>;
+  permissionOverwrites?: readonly OverwriteResolvable[] | ReadonlyCollection<Snowflake, OverwriteResolvable>;
   topic?: string;
   type?: CategoryChannelType;
   nsfw?: boolean;
@@ -5028,7 +5054,7 @@ export interface CategoryCreateChannelOptions {
   rtcRegion?: string;
   videoQualityMode?: VideoQualityMode;
   defaultThreadRateLimitPerUser?: number;
-  availableTags?: GuildForumTagData[];
+  availableTags?: readonly GuildForumTagData[];
   defaultReactionEmoji?: DefaultReactionEmoji;
   defaultAutoArchiveDuration?: ThreadAutoArchiveDuration;
   defaultSortOrder?: SortOrderType;
@@ -5102,9 +5128,9 @@ export interface ClientEvents {
   guildMemberAvailable: [member: GuildMember | PartialGuildMember];
   guildMemberRemove: [member: GuildMember | PartialGuildMember];
   guildMembersChunk: [
-    members: Collection<Snowflake, GuildMember>,
+    members: ReadonlyCollection<Snowflake, GuildMember>,
     guild: Guild,
-    data: { index: number; count: number; notFound: unknown[]; nonce: string | undefined },
+    data: { index: number; count: number; notFound: readonly unknown[]; nonce: string | undefined },
   ];
   guildMemberUpdate: [oldMember: GuildMember | PartialGuildMember, newMember: GuildMember];
   guildUpdate: [oldGuild: Guild, newGuild: Guild];
@@ -5114,10 +5140,13 @@ export interface ClientEvents {
   messageDelete: [message: Message | PartialMessage];
   messageReactionRemoveAll: [
     message: Message | PartialMessage,
-    reactions: Collection<string | Snowflake, MessageReaction>,
+    reactions: ReadonlyCollection<string | Snowflake, MessageReaction>,
   ];
   messageReactionRemoveEmoji: [reaction: MessageReaction | PartialMessageReaction];
-  messageDeleteBulk: [messages: Collection<Snowflake, Message | PartialMessage>, channel: GuildTextBasedChannel];
+  messageDeleteBulk: [
+    messages: ReadonlyCollection<Snowflake, Message | PartialMessage>,
+    channel: GuildTextBasedChannel,
+  ];
   messageReactionAdd: [reaction: MessageReaction | PartialMessageReaction, user: User | PartialUser];
   messageReactionRemove: [reaction: MessageReaction | PartialMessageReaction, user: User | PartialUser];
   messageUpdate: [oldMessage: Message | PartialMessage, newMessage: Message | PartialMessage];
@@ -5129,11 +5158,11 @@ export interface ClientEvents {
   roleUpdate: [oldRole: Role, newRole: Role];
   threadCreate: [thread: AnyThreadChannel, newlyCreated: boolean];
   threadDelete: [thread: AnyThreadChannel];
-  threadListSync: [threads: Collection<Snowflake, AnyThreadChannel>, guild: Guild];
+  threadListSync: [threads: ReadonlyCollection<Snowflake, AnyThreadChannel>, guild: Guild];
   threadMemberUpdate: [oldMember: ThreadMember, newMember: ThreadMember];
   threadMembersUpdate: [
-    addedMembers: Collection<Snowflake, ThreadMember>,
-    removedMembers: Collection<Snowflake, ThreadMember | PartialThreadMember>,
+    addedMembers: ReadonlyCollection<Snowflake, ThreadMember>,
+    removedMembers: ReadonlyCollection<Snowflake, ThreadMember | PartialThreadMember>,
     thread: AnyThreadChannel,
   ];
   threadUpdate: [oldThread: AnyThreadChannel, newThread: AnyThreadChannel];
@@ -5170,12 +5199,12 @@ export interface ClientFetchInviteOptions {
 }
 
 export interface ClientOptions {
-  shards?: number | number[] | 'auto';
+  shards?: number | readonly number[] | 'auto';
   shardCount?: number;
   closeTimeout?: number;
   makeCache?: CacheFactory;
   allowedMentions?: MessageMentionOptions;
-  partials?: Partials[];
+  partials?: readonly Partials[];
   failIfNotExists?: boolean;
   presence?: PresenceData;
   intents: BitFieldResolvable<GatewayIntentsString, number>;
@@ -5234,7 +5263,7 @@ export interface CommandInteractionOption<Cached extends CacheType = CacheType>
   value?: string | number | boolean;
   focused?: boolean;
   autocomplete?: boolean;
-  options?: CommandInteractionOption[];
+  options?: readonly CommandInteractionOption[];
   user?: User;
   member?: CacheTypeReducer<Cached, GuildMember, APIInteractionDataResolvedGuildMember>;
   channel?: CacheTypeReducer<Cached, GuildBasedChannel, APIInteractionDataResolvedChannel>;
@@ -5244,12 +5273,12 @@ export interface CommandInteractionOption<Cached extends CacheType = CacheType>
 }
 
 export interface CommandInteractionResolvedData<Cached extends CacheType = CacheType> {
-  users?: Collection<Snowflake, User>;
-  members?: Collection<Snowflake, CacheTypeReducer<Cached, GuildMember, APIInteractionDataResolvedGuildMember>>;
-  roles?: Collection<Snowflake, CacheTypeReducer<Cached, Role, APIRole>>;
-  channels?: Collection<Snowflake, CacheTypeReducer<Cached, Channel, APIInteractionDataResolvedChannel>>;
-  messages?: Collection<Snowflake, CacheTypeReducer<Cached, Message, APIMessage>>;
-  attachments?: Collection<Snowflake, Attachment>;
+  users?: ReadonlyCollection<Snowflake, User>;
+  members?: ReadonlyCollection<Snowflake, CacheTypeReducer<Cached, GuildMember, APIInteractionDataResolvedGuildMember>>;
+  roles?: ReadonlyCollection<Snowflake, CacheTypeReducer<Cached, Role, APIRole>>;
+  channels?: ReadonlyCollection<Snowflake, CacheTypeReducer<Cached, Channel, APIInteractionDataResolvedChannel>>;
+  messages?: ReadonlyCollection<Snowflake, CacheTypeReducer<Cached, Message, APIMessage>>;
+  attachments?: ReadonlyCollection<Snowflake, Attachment>;
 }
 
 export interface AutocompleteFocusedOption extends Pick<CommandInteractionOption, 'name'> {
@@ -5498,8 +5527,8 @@ export interface FetchChannelOptions extends BaseFetchOptions {
 }
 
 export interface FetchedThreads {
-  threads: Collection<Snowflake, AnyThreadChannel>;
-  members: Collection<Snowflake, ThreadMember>;
+  threads: ReadonlyCollection<Snowflake, AnyThreadChannel>;
+  members: ReadonlyCollection<Snowflake, ThreadMember>;
 }
 
 export interface FetchedThreadsMore extends FetchedThreads {
@@ -5546,7 +5575,7 @@ export interface FetchMemberOptions extends BaseFetchOptions {
 }
 
 export interface FetchMembersOptions {
-  user?: UserResolvable | UserResolvable[];
+  user?: UserResolvable | readonly UserResolvable[];
   query?: string;
   limit?: number;
   withPresences?: boolean;
@@ -5752,10 +5781,10 @@ export interface AutoModerationRuleCreateOptions {
   eventType: AutoModerationRuleEventType;
   triggerType: AutoModerationRuleTriggerType;
   triggerMetadata?: AutoModerationTriggerMetadataOptions;
-  actions: AutoModerationActionOptions[];
+  actions: readonly AutoModerationActionOptions[];
   enabled?: boolean;
-  exemptRoles?: Collection<Snowflake, Role> | RoleResolvable[];
-  exemptChannels?: Collection<Snowflake, GuildBasedChannel> | GuildChannelResolvable[];
+  exemptRoles?: ReadonlyCollection<Snowflake, Role> | readonly RoleResolvable[];
+  exemptChannels?: ReadonlyCollection<Snowflake, GuildBasedChannel> | readonly GuildChannelResolvable[];
   reason?: string;
 }
 
@@ -5799,11 +5828,11 @@ export interface GuildChannelEditOptions {
   parent?: CategoryChannelResolvable | null;
   rateLimitPerUser?: number;
   lockPermissions?: boolean;
-  permissionOverwrites?: readonly OverwriteResolvable[] | Collection<Snowflake, OverwriteResolvable>;
+  permissionOverwrites?: readonly OverwriteResolvable[] | ReadonlyCollection<Snowflake, OverwriteResolvable>;
   defaultAutoArchiveDuration?: ThreadAutoArchiveDuration;
   rtcRegion?: string | null;
   videoQualityMode?: VideoQualityMode | null;
-  availableTags?: GuildForumTagData[];
+  availableTags?: readonly GuildForumTagData[];
   defaultReactionEmoji?: DefaultReactionEmoji | null;
   defaultThreadRateLimitPerUser?: number;
   flags?: ChannelFlagsResolvable;
@@ -5823,8 +5852,8 @@ export interface GuildCreateOptions {
   verificationLevel?: GuildVerificationLevel;
   defaultMessageNotifications?: GuildDefaultMessageNotifications;
   explicitContentFilter?: GuildExplicitContentFilter;
-  roles?: PartialRoleData[];
-  channels?: PartialChannelData[];
+  roles?: readonly PartialRoleData[];
+  channels?: readonly PartialChannelData[];
   afkChannelId?: Snowflake | number;
   afkTimeout?: number;
   systemChannelId?: Snowflake | number;
@@ -5854,7 +5883,7 @@ export interface GuildEditOptions {
   publicUpdatesChannel?: TextChannelResolvable | null;
   safetyAlertsChannel?: TextChannelResolvable | null;
   preferredLocale?: Locale | null;
-  features?: `${GuildFeature}`[];
+  features?: readonly `${GuildFeature}`[];
   description?: string | null;
   premiumProgressBarEnabled?: boolean;
   reason?: string;
@@ -5863,13 +5892,13 @@ export interface GuildEditOptions {
 export interface GuildEmojiCreateOptions {
   attachment: BufferResolvable | Base64Resolvable;
   name: string;
-  roles?: Collection<Snowflake, Role> | RoleResolvable[];
+  roles?: ReadonlyCollection<Snowflake, Role> | readonly RoleResolvable[];
   reason?: string;
 }
 
 export interface GuildEmojiEditOptions {
   name?: string;
-  roles?: Collection<Snowflake, Role> | RoleResolvable[];
+  roles?: ReadonlyCollection<Snowflake, Role> | readonly RoleResolvable[];
   reason?: string;
 }
 
@@ -5890,7 +5919,7 @@ export interface GuildStickerEditOptions {
 
 export interface GuildMemberEditOptions {
   nick?: string | null;
-  roles?: Collection<Snowflake, Role> | readonly RoleResolvable[];
+  roles?: ReadonlyCollection<Snowflake, Role> | readonly RoleResolvable[];
   mute?: boolean;
   deaf?: boolean;
   channel?: GuildVoiceChannelResolvable | null;
@@ -5908,7 +5937,7 @@ export interface GuildPruneMembersOptions {
   days?: number;
   dry?: boolean;
   reason?: string;
-  roles?: RoleResolvable[];
+  roles?: readonly RoleResolvable[];
 }
 
 export interface GuildWidgetSettingsData {
@@ -6074,7 +6103,7 @@ export interface InviteGenerationOptions {
   permissions?: PermissionResolvable;
   guild?: GuildResolvable;
   disableGuildSelect?: boolean;
-  scopes: OAuth2Scopes[];
+  scopes: readonly OAuth2Scopes[];
 }
 
 export type GuildInvitableChannelResolvable =
@@ -6194,9 +6223,9 @@ export interface MessageMentionsHasOptions {
 }
 
 export interface MessageMentionOptions {
-  parse?: MessageMentionTypes[];
-  roles?: Snowflake[];
-  users?: Snowflake[];
+  parse?: readonly MessageMentionTypes[];
+  roles?: readonly Snowflake[];
+  users?: readonly Snowflake[];
   repliedUser?: boolean;
 }
 
@@ -6204,9 +6233,9 @@ export type MessageMentionTypes = 'roles' | 'users' | 'everyone';
 
 export interface BaseMessageOptions {
   content?: string;
-  embeds?: (JSONEncodable<APIEmbed> | APIEmbed)[];
+  embeds?: readonly (JSONEncodable<APIEmbed> | APIEmbed)[];
   allowedMentions?: MessageMentionOptions;
-  files?: (
+  files?: readonly (
     | BufferResolvable
     | Stream
     | JSONEncodable<APIAttachment>
@@ -6214,7 +6243,7 @@ export interface BaseMessageOptions {
     | AttachmentBuilder
     | AttachmentPayload
   )[];
-  components?: (
+  components?: readonly (
     | JSONEncodable<APIActionRowComponent<APIMessageActionRowComponent>>
     | ActionRowData<MessageActionRowComponentData | MessageActionRowComponentBuilder>
     | APIActionRowComponent<APIMessageActionRowComponent>
@@ -6226,7 +6255,7 @@ export interface MessageCreateOptions extends BaseMessageOptions {
   nonce?: string | number;
   enforceNonce?: boolean;
   reply?: ReplyOptions;
-  stickers?: StickerResolvable[];
+  stickers?: readonly StickerResolvable[];
   flags?: BitFieldResolvable<
     Extract<MessageFlagsString, 'SuppressEmbeds' | 'SuppressNotifications'>,
     MessageFlags.SuppressEmbeds | MessageFlags.SuppressNotifications
@@ -6243,7 +6272,7 @@ export interface MessageEditAttachmentData {
 
 export interface MessageEditOptions extends Omit<BaseMessageOptions, 'content'> {
   content?: string | null;
-  attachments?: (Attachment | MessageEditAttachmentData)[];
+  attachments?: readonly (Attachment | MessageEditAttachmentData)[];
   flags?: BitFieldResolvable<Extract<MessageFlagsString, 'SuppressEmbeds'>, MessageFlags.SuppressEmbeds>;
 }
 
@@ -6267,7 +6296,7 @@ export interface BaseSelectMenuComponentData extends BaseComponentData {
 
 export interface StringSelectMenuComponentData extends BaseSelectMenuComponentData {
   type: ComponentType.StringSelect;
-  options: SelectMenuComponentOptionData[];
+  options: readonly SelectMenuComponentOptionData[];
 }
 
 export interface UserSelectMenuComponentData extends BaseSelectMenuComponentData {
@@ -6284,7 +6313,7 @@ export interface MentionableSelectMenuComponentData extends BaseSelectMenuCompon
 
 export interface ChannelSelectMenuComponentData extends BaseSelectMenuComponentData {
   type: ComponentType.ChannelSelect;
-  channelTypes?: ChannelType[];
+  channelTypes?: readonly ChannelType[];
 }
 
 export interface MessageSelectOption {
@@ -6364,8 +6393,8 @@ export interface PartialRecipient {
 export interface PresenceData {
   status?: PresenceStatusData;
   afk?: boolean;
-  activities?: ActivitiesOptions[];
-  shardId?: number | number[];
+  activities?: readonly ActivitiesOptions[];
+  shardId?: number | readonly number[];
 }
 
 export type PresenceResolvable = Presence | UserResolvable | Snowflake;
@@ -6381,7 +6410,7 @@ export interface PartialChannelData {
   userLimit?: number;
   rtcRegion?: string | null;
   videoQualityMode?: VideoQualityMode;
-  permissionOverwrites?: PartialOverwriteData[];
+  permissionOverwrites?: readonly PartialOverwriteData[];
   rateLimitPerUser?: number;
 }
 
@@ -6528,13 +6557,13 @@ export type ShardingManagerMode = 'process' | 'worker';
 
 export interface ShardingManagerOptions {
   totalShards?: number | 'auto';
-  shardList?: number[] | 'auto';
+  shardList?: readonly number[] | 'auto';
   mode?: ShardingManagerMode;
   respawn?: boolean;
   silent?: boolean;
-  shardArgs?: string[];
+  shardArgs?: readonly string[];
   token?: string;
-  execArgv?: string[];
+  execArgv?: readonly string[];
 }
 
 export { Snowflake };
@@ -6661,7 +6690,7 @@ export interface GuildTextThreadCreateOptions<AllowedThreadType> extends StartTh
 
 export interface GuildForumThreadCreateOptions extends StartThreadOptions {
   message: GuildForumThreadMessageCreateOptions | MessagePayload;
-  appliedTags?: Snowflake[];
+  appliedTags?: readonly Snowflake[];
 }
 
 export interface ThreadEditOptions {
@@ -6671,7 +6700,7 @@ export interface ThreadEditOptions {
   rateLimitPerUser?: number;
   locked?: boolean;
   invitable?: boolean;
-  appliedTags?: Snowflake[];
+  appliedTags?: readonly Snowflake[];
   flags?: ChannelFlagsResolvable;
   reason?: string;
 }
@@ -6738,7 +6767,7 @@ export interface WebhookMessageCreateOptions extends Omit<MessageCreateOptions,
   avatarURL?: string;
   threadId?: Snowflake;
   threadName?: string;
-  appliedTags?: Snowflake[];
+  appliedTags?: readonly Snowflake[];
 }
 
 export interface WebSocketOptions {
@@ -6767,7 +6796,7 @@ export interface WelcomeChannelData {
 export interface WelcomeScreenEditOptions {
   enabled?: boolean;
   description?: string;
-  welcomeChannels?: WelcomeChannelData[];
+  welcomeChannels?: readonly WelcomeChannelData[];
 }
 
 export interface ClientApplicationEditOptions {
@@ -6783,7 +6812,7 @@ export interface ClientApplicationEditOptions {
 }
 
 export interface ClientApplicationInstallParams {
-  scopes: OAuth2Scopes[];
+  scopes: readonly OAuth2Scopes[];
   permissions: Readonly<PermissionsBitField>;
 }
 
diff --git a/packages/discord.js/typings/index.test-d.ts b/packages/discord.js/typings/index.test-d.ts
index b7d9d6222..679c9ad69 100644
--- a/packages/discord.js/typings/index.test-d.ts
+++ b/packages/discord.js/typings/index.test-d.ts
@@ -193,6 +193,7 @@ import {
 } from '.';
 import { expectAssignable, expectNotAssignable, expectNotType, expectType } from 'tsd';
 import type { ContextMenuCommandBuilder, SlashCommandBuilder } from '@discordjs/builders';
+import { ReadonlyCollection } from '@discordjs/collection';
 
 // Test type transformation:
 declare const serialize: <Value>(value: Value) => Serialized<Value>;
@@ -1171,8 +1172,8 @@ client.on('threadMembersUpdate', (addedMembers, removedMembers, thread) => {
   expectType<Client<true>>(addedMembers.first()!.client);
   expectType<Client<true>>(removedMembers.first()!.client);
   expectType<Client<true>>(thread.client);
-  expectType<Collection<Snowflake, ThreadMember>>(addedMembers);
-  expectType<Collection<Snowflake, ThreadMember | PartialThreadMember>>(removedMembers);
+  expectType<ReadonlyCollection<Snowflake, ThreadMember>>(addedMembers);
+  expectType<ReadonlyCollection<Snowflake, ThreadMember | PartialThreadMember>>(removedMembers);
   expectType<AnyThreadChannel>(thread);
   const left = removedMembers.first();
   if (!left) return;
@@ -1990,7 +1991,7 @@ client.on('interactionCreate', async interaction => {
     const requiredOption = interaction.options.get('name', true);
     expectType<CommandInteractionOption | null>(optionalOption);
     expectType<CommandInteractionOption>(requiredOption);
-    expectType<CommandInteractionOption[] | undefined>(requiredOption.options);
+    expectType<readonly CommandInteractionOption[] | undefined>(requiredOption.options);
 
     expectType<string | null>(interaction.options.getString('name', booleanValue));
     expectType<string | null>(interaction.options.getString('name', false));
@@ -2082,7 +2083,7 @@ collector.on('dispose', (vals, ...other) => {
 });
 
 collector.on('end', (collection, reason) => {
-  expectType<Collection<string, Interaction>>(collection);
+  expectType<ReadonlyCollection<string, Interaction>>(collection);
   expectType<string>(reason);
 });