diff --git a/packages/backend/src/core/activitypub/ApInboxService.ts b/packages/backend/src/core/activitypub/ApInboxService.ts
index efef777fb0..114a39b9c8 100644
--- a/packages/backend/src/core/activitypub/ApInboxService.ts
+++ b/packages/backend/src/core/activitypub/ApInboxService.ts
@@ -24,7 +24,7 @@ import { QueueService } from '@/core/QueueService.js';
 import type { UsersRepository, NotesRepository, FollowingsRepository, AbuseUserReportsRepository, FollowRequestsRepository, } from '@/models/index.js';
 import { bindThis } from '@/decorators.js';
 import type { RemoteUser } from '@/models/entities/User.js';
-import { getApHrefNullable, getApId, getApIds, getApType, getOneApHrefNullable, isAccept, isActor, isAdd, isAnnounce, isBlock, isCollection, isCollectionOrOrderedCollection, isCreate, isDelete, isFlag, isFollow, isLike, isMove, isPost, isReject, isRemove, isTombstone, isUndo, isUpdate, validActor, validPost } from './type.js';
+import { getApHrefNullable, getApId, getApIds, getApType, getOneApHrefNullable, isAccept, isActor, isAdd, isAnnounce, isBlock, isCollection, isCollectionOrOrderedCollection, isCreate, isDelete, isFlag, isFollow, isLike, isMove, isOrderedCollectionPage, isPost, isReject, isRemove, isTombstone, isUndo, isUpdate, validActor, validPost } from './type.js';
 import { ApNoteService } from './models/ApNoteService.js';
 import { ApLoggerService } from './ApLoggerService.js';
 import { ApDbResolverService } from './ApDbResolverService.js';
@@ -86,10 +86,10 @@ export class ApInboxService {
 	}
 
 	@bindThis
-	public async performActivity(actor: RemoteUser, activity: IObject) {
-		if (isCollectionOrOrderedCollection(activity)) {
+	public async performActivity(actor: RemoteUser, activity: IObject, limit = Infinity) {
+		if (isCollectionOrOrderedCollection(activity) || isOrderedCollectionPage(activity)) {
 			const resolver = this.apResolverService.createResolver();
-			for (const item of toArray(isCollection(activity) ? activity.items : activity.orderedItems)) {
+			for (const item of toArray(isCollection(activity) ? activity.items : activity.orderedItems).slice(0, limit)) {
 				const act = await resolver.resolve(item);
 				try {
 					await this.performOneActivity(actor, act);
@@ -366,7 +366,7 @@ export class ApInboxService {
 		});
 
 		if (isPost(object)) {
-			this.createNote(resolver, actor, object, false, activity);
+			await this.createNote(resolver, actor, object, false, activity);
 		} else {
 			this.logger.warn(`Unknown type: ${getApType(object)}`);
 		}
diff --git a/packages/backend/src/core/activitypub/ApResolverService.ts b/packages/backend/src/core/activitypub/ApResolverService.ts
index d3e0345c9c..62dcad68df 100644
--- a/packages/backend/src/core/activitypub/ApResolverService.ts
+++ b/packages/backend/src/core/activitypub/ApResolverService.ts
@@ -10,11 +10,11 @@ import { UtilityService } from '@/core/UtilityService.js';
 import { bindThis } from '@/decorators.js';
 import { LoggerService } from '@/core/LoggerService.js';
 import type Logger from '@/logger.js';
-import { isCollectionOrOrderedCollection } from './type.js';
+import { isCollectionOrOrderedCollection, isOrderedCollectionPage } from './type.js';
 import { ApDbResolverService } from './ApDbResolverService.js';
 import { ApRendererService } from './ApRendererService.js';
 import { ApRequestService } from './ApRequestService.js';
-import type { IObject, ICollection, IOrderedCollection } from './type.js';
+import type { IObject, ICollection, IOrderedCollection, IOrderedCollectionPage } from './type.js';
 
 export class Resolver {
 	private history: Set<string>;
@@ -59,6 +59,18 @@ export class Resolver {
 		}
 	}
 
+	public async resolveOrderedCollectionPage(value: string | IObject): Promise<IOrderedCollectionPage> {
+		const collection = typeof value === 'string'
+			? await this.resolve(value)
+			: value;
+
+		if (isOrderedCollectionPage(collection)) {
+			return collection;
+		} else {
+			throw new Error(`unrecognized collection type: ${collection.type}`);
+		}
+	}
+
 	@bindThis
 	public async resolve(value: string | IObject): Promise<IObject> {
 		if (value == null) {
diff --git a/packages/backend/src/core/activitypub/models/ApPersonService.ts b/packages/backend/src/core/activitypub/models/ApPersonService.ts
index f52ebed107..8fb83b553b 100644
--- a/packages/backend/src/core/activitypub/models/ApPersonService.ts
+++ b/packages/backend/src/core/activitypub/models/ApPersonService.ts
@@ -34,7 +34,8 @@ import { MetaService } from '@/core/MetaService.js';
 import { DriveFileEntityService } from '@/core/entities/DriveFileEntityService.js';
 import type { AccountMoveService } from '@/core/AccountMoveService.js';
 import { checkHttps } from '@/misc/check-https.js';
-import { getApId, getApType, getOneApHrefNullable, isActor, isCollection, isCollectionOrOrderedCollection, isPropertyValue } from '../type.js';
+import { getApId, getApType, getOneApHrefNullable, isActor, isCollection, isCollectionOrOrderedCollection, isOrderedCollection, isOrderedCollectionPage, isPropertyValue } from '../type.js';
+import { ApInboxService } from '../ApInboxService.js';
 import { extractApHashtags } from './tag.js';
 import type { OnModuleInit } from '@nestjs/common';
 import type { ApNoteService } from './ApNoteService.js';
@@ -62,6 +63,7 @@ export class ApPersonService implements OnModuleInit {
 	private apResolverService: ApResolverService;
 	private apNoteService: ApNoteService;
 	private apImageService: ApImageService;
+	private apInboxService: ApInboxService;
 	private apMfmService: ApMfmService;
 	private mfmService: MfmService;
 	private hashtagService: HashtagService;
@@ -128,6 +130,7 @@ export class ApPersonService implements OnModuleInit {
 		this.apResolverService = this.moduleRef.get('ApResolverService');
 		this.apNoteService = this.moduleRef.get('ApNoteService');
 		this.apImageService = this.moduleRef.get('ApImageService');
+		this.apInboxService = this.moduleRef.get('ApInboxService');
 		this.apMfmService = this.moduleRef.get('ApMfmService');
 		this.mfmService = this.moduleRef.get('MfmService');
 		this.hashtagService = this.moduleRef.get('HashtagService');
@@ -281,7 +284,7 @@ export class ApPersonService implements OnModuleInit {
 		// Create user
 		let user: RemoteUser;
 		try {
-		// Start transaction
+			// Start transaction
 			await this.db.transaction(async transactionalEntityManager => {
 				user = await transactionalEntityManager.save(new User({
 					id: this.idService.genId(),
@@ -327,9 +330,9 @@ export class ApPersonService implements OnModuleInit {
 				}
 			});
 		} catch (e) {
-		// duplicate key error
+			// duplicate key error
 			if (isDuplicateKeyValueError(e)) {
-			// /users/@a => /users/:id のように入力がaliasなときにエラーになることがあるのを対応
+				// /users/@a => /users/:id のように入力がaliasなときにエラーになることがあるのを対応
 				const u = await this.usersRepository.findOneBy({
 					uri: person.id,
 				});
@@ -406,7 +409,10 @@ export class ApPersonService implements OnModuleInit {
 		});
 		//#endregion
 
-		await this.updateFeatured(user!.id, resolver).catch(err => this.logger.error(err));
+		await Promise.all([
+			this.updateFeatured(user!.id, resolver),
+			this.updateOutboxFirstPage(user!, person.outbox, resolver),
+		]).catch(err => this.logger.error(err));
 
 		return user!;
 	}
@@ -415,7 +421,7 @@ export class ApPersonService implements OnModuleInit {
 	 * Personの情報を更新します。
 	 * Misskeyに対象のPersonが登録されていなければ無視します。
 	 * もしアカウントの移行が確認された場合、アカウント移行処理を行います。
-	 * 
+	 *
 	 * @param uri URI of Person
 	 * @param resolver Resolver
 	 * @param hint Hint of Person object (この値が正当なPersonの場合、Remote resolveをせずに更新に利用します)
@@ -498,7 +504,7 @@ export class ApPersonService implements OnModuleInit {
 			(!exist.movedToUri && updates.movedToUri) ||
 			// 移行先がある→別のもの
 			(exist.movedToUri !== updates.movedToUri && exist.movedToUri && updates.movedToUri);
-			// 移行先がある→ない、ない→ないは無視
+		// 移行先がある→ない、ない→ないは無視
 
 		if (moving) updates.movedAt = new Date();
 
@@ -598,9 +604,9 @@ export class ApPersonService implements OnModuleInit {
 	@bindThis
 	public analyzeAttachments(attachments: IObject | IObject[] | undefined) {
 		const fields: {
-		name: string,
-		value: string
-	}[] = [];
+			name: string,
+			value: string
+		}[] = [];
 		if (Array.isArray(attachments)) {
 			for (const attachment of attachments.filter(isPropertyValue)) {
 				fields.push({
@@ -613,8 +619,35 @@ export class ApPersonService implements OnModuleInit {
 		return { fields };
 	}
 
+	/**
+	 * Retrieve outbox from an actor object.
+	 *
+	 * This only retrieves the first page for now.
+	 */
+	public async updateOutboxFirstPage(user: RemoteUser, outbox: IActor['outbox'], resolver: Resolver): Promise<void> {
+		// https://www.w3.org/TR/activitypub/#actor-objects
+		// Outbox is a required property for all actors
+		if (!outbox) {
+			throw new Error('No outbox property');
+		}
+
+		this.logger.info(`Fetching the outbox for ${user.uri}: ${outbox}`);
+
+		const collection = await resolver.resolveCollection(outbox);
+		if (!isOrderedCollection(collection)) {
+			throw new Error('Outbox must be an ordered collection');
+		}
+
+		const firstPage = collection.first ?
+			await resolver.resolveOrderedCollectionPage(collection.first) :
+			collection;
+
+		// Perform activity but only the first 100 ones
+		await this.apInboxService.performActivity(user, firstPage, 100);
+	}
+
 	@bindThis
-	public async updateFeatured(userId: User['id'], resolver?: Resolver) {
+	public async updateFeatured(userId: User['id'], resolver?: Resolver): Promise<void> {
 		const user = await this.usersRepository.findOneByOrFail({ id: userId });
 		if (!this.userEntityService.isRemoteUser(user)) return;
 		if (!user.featured) return;
@@ -631,7 +664,7 @@ export class ApPersonService implements OnModuleInit {
 		const unresolvedItems = isCollection(collection) ? collection.items : collection.orderedItems;
 		const items = await Promise.all(toArray(unresolvedItems).map(x => _resolver.resolve(x)));
 
-		// Resolve and regist Notes
+		// Resolve and register Notes
 		const limit = promiseLimit<Note | null>(2);
 		const featuredNotes = await Promise.all(items
 			.filter(item => getApType(item) === 'Note')	// TODO: Noteでなくてもいいかも
@@ -688,7 +721,7 @@ export class ApPersonService implements OnModuleInit {
 			// (uriが存在しなかったり応答がなかったりする場合resolvePersonはthrow Errorする)
 			dst = await this.resolvePerson(src.movedToUri);
 		}
- 
+
 		if (dst.movedToUri === dst.uri) return 'skip: movedTo itself (dst)'; // ？？？
 		if (src.movedToUri !== dst.uri) return 'skip: missmatch uri'; // ？？？
 		if (dst.movedToUri === src.uri) return 'skip: dst.movedToUri === src.uri';
diff --git a/packages/backend/src/core/activitypub/type.ts b/packages/backend/src/core/activitypub/type.ts
index 625135da6c..58371c8fe5 100644
--- a/packages/backend/src/core/activitypub/type.ts
+++ b/packages/backend/src/core/activitypub/type.ts
@@ -87,16 +87,37 @@ export interface IActivity extends IObject {
 	};
 }
 
+// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-collection
 export interface ICollection extends IObject {
 	type: 'Collection';
 	totalItems: number;
+	current?: ICollectionPage | string;
+	first?: ICollectionPage | string;
+	last?: ICollectionPage | string;
 	items: ApObject;
 }
 
-export interface IOrderedCollection extends IObject {
+// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-orderedcollection
+export interface IOrderedCollection extends Omit<ICollection, 'type' | 'items'> {
 	type: 'OrderedCollection';
-	totalItems: number;
-	orderedItems: ApObject;
+
+	// orderedItems is not defined well
+	// https://github.com/w3c/activitystreams/issues/494
+	orderedItems?: ApObject;
+}
+
+// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-collectionpage
+export interface ICollectionPage extends Omit<ICollection, 'type'> {
+	type: 'CollectionPage';
+	partOf?: ICollection | string;
+	next?: ICollectionPage | string;
+	prev?: ICollectionPage | string;
+}
+
+// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-orderedcollectionpage
+export interface IOrderedCollectionPage extends Omit<IOrderedCollection, 'type'>, Omit<ICollectionPage, 'type' | 'items'> {
+	type: 'OrderedCollectionPage';
+	startIndex?: number,
 }
 
 export const validPost = ['Note', 'Question', 'Article', 'Audio', 'Document', 'Image', 'Page', 'Video', 'Event'];
@@ -183,6 +204,9 @@ export const isCollection = (object: IObject): object is ICollection =>
 export const isOrderedCollection = (object: IObject): object is IOrderedCollection =>
 	getApType(object) === 'OrderedCollection';
 
+export const isOrderedCollectionPage = (object: IObject): object is IOrderedCollectionPage =>
+	getApType(object) === 'OrderedCollectionPage';
+
 export const isCollectionOrOrderedCollection = (object: IObject): object is ICollection | IOrderedCollection =>
 	isCollection(object) || isOrderedCollection(object);
 
diff --git a/packages/backend/test/unit/activitypub.ts b/packages/backend/test/unit/activitypub.ts
index 7cd740a2fa..2b43437348 100644
--- a/packages/backend/test/unit/activitypub.ts
+++ b/packages/backend/test/unit/activitypub.ts
@@ -11,7 +11,7 @@ import { GlobalModule } from '@/GlobalModule.js';
 import { CoreModule } from '@/core/CoreModule.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
 import { LoggerService } from '@/core/LoggerService.js';
-import type { IActor } from '@/core/activitypub/type.js';
+import type { IActor, ICreate, IObject, IOrderedCollection, IOrderedCollectionPage, IPost } from '@/core/activitypub/type.js';
 import { Note } from '@/models/index.js';
 import { secureRndstr } from '@/misc/secure-rndstr.js';
 import { MockResolver } from '../misc/mock-resolver.js';
@@ -32,6 +32,59 @@ function createRandomActor(): IActor & { id: string } {
 	};
 }
 
+function createRandomCreateActivity(actor: IActor, length: number): ICreate[] {
+	return new Array(length).fill(null).map((): ICreate => {
+		const id = secureRndstr(8);
+		const noteId = `${host}/notes/${id}`;
+
+		return {
+			type: 'Create',
+			id: `${noteId}/activity`,
+			actor,
+			object: {
+				id: noteId,
+				type: 'Note',
+				attributedTo: actor.id,
+				content: 'test test foo',
+			} satisfies IPost,
+		};
+	});
+}
+
+function createRandomNonPagedOutbox(actor: IActor, length: number): IOrderedCollection {
+	const orderedItems = createRandomCreateActivity(actor, length);
+
+	return {
+		'@context': 'https://www.w3.org/ns/activitystreams',
+		type: 'OrderedCollection',
+		id: actor.outbox as string,
+		totalItems: orderedItems.length,
+		orderedItems,
+	};
+}
+
+function createRandomOutboxPage(actor: IActor, id: string, length: number): IOrderedCollectionPage {
+	const orderedItems = createRandomCreateActivity(actor, length);
+
+	return {
+		'@context': 'https://www.w3.org/ns/activitystreams',
+		type: 'OrderedCollectionPage',
+		id,
+		totalItems: orderedItems.length,
+		orderedItems,
+	};
+}
+
+function createRandomPagedOutbox(actor: IActor): IOrderedCollection {
+	return {
+		'@context': 'https://www.w3.org/ns/activitystreams',
+		type: 'OrderedCollection',
+		id: actor.outbox as string,
+		totalItems: 10,
+		first: `${actor.outbox}?first`,
+	};
+}
+
 describe('ActivityPub', () => {
 	let noteService: ApNoteService;
 	let personService: ApPersonService;
@@ -53,7 +106,7 @@ describe('ActivityPub', () => {
 
 		// Prevent ApPersonService from fetching instance, as it causes Jest import-after-test error
 		const federatedInstanceService = app.get<FederatedInstanceService>(FederatedInstanceService);
-		jest.spyOn(federatedInstanceService, 'fetch').mockImplementation(() => new Promise(() => {}));
+		jest.spyOn(federatedInstanceService, 'fetch').mockImplementation(() => new Promise(() => { }));
 	});
 
 	describe('Parse minimum object', () => {
@@ -126,4 +179,74 @@ describe('ActivityPub', () => {
 			} as Note);
 		});
 	});
+
+	describe('Outbox', () => {
+		test('Fetch non-paged outbox from IActor', async () => {
+			const actor = createRandomActor();
+			const outbox = createRandomNonPagedOutbox(actor, 10);
+
+			resolver._register(actor.id, actor);
+			resolver._register(actor.outbox as string, outbox);
+
+			// XXX: This shouldn't be needed as the collection already has the full information
+			// But somehow the resolver currently doesn't use it at all and always fetches again
+			for (const item of outbox.orderedItems as IObject[]) {
+				resolver._register(item.id!, item);
+			}
+
+			await personService.createPerson(actor.id, resolver);
+
+			for (const item of outbox.orderedItems as ICreate[]) {
+				const note = await noteService.fetchNote(item.object);
+				assert.ok(note);
+				assert.strictEqual(note.text, 'test test foo');
+				assert.strictEqual(note.uri, (item.object as IObject).id);
+			}
+		});
+
+		test('Fetch paged outbox from IActor', async () => {
+			const actor = createRandomActor();
+			const outbox = createRandomPagedOutbox(actor);
+			const page = createRandomOutboxPage(actor, outbox.id!, 10);
+
+			resolver._register(actor.id, actor);
+			resolver._register(actor.outbox as string, outbox);
+			resolver._register(outbox.first as string, page);
+
+			// XXX: This shouldn't be needed as the collection already has the full information
+			// But somehow the resolver currently doesn't use it at all and always fetches again
+			for (const item of page.orderedItems as IObject[]) {
+				resolver._register(item.id!, item);
+			}
+
+			await personService.createPerson(actor.id, resolver);
+
+			for (const item of page.orderedItems as ICreate[]) {
+				const note = await noteService.fetchNote(item.object);
+				assert.ok(note);
+				assert.strictEqual(note.text, 'test test foo');
+				assert.strictEqual(note.uri, (item.object as IObject).id);
+			}
+		});
+
+		test('Fetch only the first 100 items', async () => {
+			const actor = createRandomActor();
+			const outbox = createRandomNonPagedOutbox(actor, 200);
+
+			resolver._register(actor.id, actor);
+			resolver._register(actor.outbox as string, outbox);
+
+			// XXX: This shouldn't be needed as the collection already has the full information
+			// But somehow the resolver currently doesn't use it at all and always fetches again
+			for (const item of outbox.orderedItems as IObject[]) {
+				resolver._register(item.id!, item);
+			}
+
+			await personService.createPerson(actor.id, resolver);
+
+			const items = outbox.orderedItems as ICreate[];
+			assert.ok(await noteService.fetchNote(items[99].object));
+			assert.ok(!await noteService.fetchNote(items[100].object));
+		});
+	});
 });