diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index 32e4fe7f8a..5d6d88e271 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -8,6 +8,7 @@ import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mf
 import { extractHashtags } from '@/misc/extract-hashtags.js';
 import type { IMentionedRemoteUsers } from '@/models/entities/Note.js';
 import { Note } from '@/models/entities/Note.js';
+import { Event, IEvent } from '@/models/entities/Event.js';
 import type { ChannelFollowingsRepository, ChannelsRepository, InstancesRepository, MutedNotesRepository, MutingsRepository, NotesRepository, NoteThreadMutingsRepository, UserProfilesRepository, UsersRepository } from '@/models/index.js';
 import type { DriveFile } from '@/models/entities/DriveFile.js';
 import type { App } from '@/models/entities/App.js';
@@ -126,6 +127,7 @@ type Option = {
 	renote?: Note | null;
 	files?: DriveFile[] | null;
 	poll?: IPoll | null;
+	event?: IEvent | null;
 	localOnly?: boolean | null;
 	reactionAcceptance?: Note['reactionAcceptance'];
 	cw?: string | null;
@@ -358,6 +360,7 @@ export class NoteCreateService implements OnApplicationShutdown {
 			name: data.name,
 			text: data.text,
 			hasPoll: data.poll != null,
+			hasEvent: data.event != null,
 			cw: data.cw == null ? null : data.cw,
 			tags: tags.map(tag => normalizeForSearch(tag)),
 			emojis,
@@ -402,23 +405,40 @@ export class NoteCreateService implements OnApplicationShutdown {
 
 		// 投稿を作成
 		try {
-			if (insert.hasPoll) {
+			if (insert.hasPoll || insert.hasEvent) {
 				// Start transaction
 				await this.db.transaction(async transactionalEntityManager => {
 					await transactionalEntityManager.insert(Note, insert);
 
-					const poll = new Poll({
-						noteId: insert.id,
-						choices: data.poll!.choices,
-						expiresAt: data.poll!.expiresAt,
-						multiple: data.poll!.multiple,
-						votes: new Array(data.poll!.choices.length).fill(0),
-						noteVisibility: insert.visibility,
-						userId: user.id,
-						userHost: user.host,
-					});
+					if (insert.hasPoll) {
+						const poll = new Poll({
+							noteId: insert.id,
+							choices: data.poll!.choices,
+							expiresAt: data.poll!.expiresAt,
+							multiple: data.poll!.multiple,
+							votes: new Array(data.poll!.choices.length).fill(0),
+							noteVisibility: insert.visibility,
+							userId: user.id,
+							userHost: user.host,
+						});
 
-					await transactionalEntityManager.insert(Poll, poll);
+						await transactionalEntityManager.insert(Poll, poll);
+					}
+
+					if (insert.hasEvent) {
+						const event = new Event({
+							noteId: insert.id,
+							start: data.event!.start,
+							end: data.event!.end ?? undefined,
+							title: data.event!.title,
+							metadata: data.event!.metadata,
+							noteVisibility: insert.visibility,
+							userId: user.id,
+							userHost: user.host,
+						});
+
+						await transactionalEntityManager.insert(Event, event);
+					}
 				});
 			} else {
 				await this.notesRepository.insert(insert);
diff --git a/packages/backend/src/server/api/endpoints/notes/create.ts b/packages/backend/src/server/api/endpoints/notes/create.ts
index 69fafcb9c7..7141c37fcd 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.ts
@@ -144,6 +144,16 @@ export const paramDef = {
 			},
 			required: ['choices'],
 		},
+		event: {
+			type: 'object',
+			nullable: true,
+			properties: {
+				title: { type: 'string', minLength: 1, maxLength: 128, nullable: false },
+				start: { type: 'integer', nullable: false },
+				end: { type: 'integer', nullable: true },
+				metadata: { type: 'object' },
+			},
+		},
 	},
 	// (re)note with text, files and poll are optional
 	anyOf: [
@@ -279,6 +289,12 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 				text: ps.text ?? undefined,
 				reply,
 				renote,
+				event: ps.event ? {
+					start: new Date(ps.event.start!),
+					end: ps.event.end ? new Date(ps.event.end) : null,
+					title: ps.event.title!,
+					metadata: ps.event.metadata ?? {},
+				} : undefined,
 				cw: ps.cw,
 				localOnly: ps.localOnly,
 				reactionAcceptance: ps.reactionAcceptance,