diff --git a/packages/backend/src/core/activitypub/ApRendererService.ts b/packages/backend/src/core/activitypub/ApRendererService.ts
index 89e5217285..ff909778e8 100644
--- a/packages/backend/src/core/activitypub/ApRendererService.ts
+++ b/packages/backend/src/core/activitypub/ApRendererService.ts
@@ -528,6 +528,7 @@ export class ApRendererService {
 			discoverable: user.isExplorable,
 			publicKey: this.renderKey(user, keypair, '#main-key'),
 			isCat: user.isCat,
+			hideOnlineStatus: user.hideOnlineStatus,
 			noindex: user.noindex,
 			indexable: !user.noindex,
 			speakAsCat: user.speakAsCat,
diff --git a/packages/backend/src/core/activitypub/misc/contexts.ts b/packages/backend/src/core/activitypub/misc/contexts.ts
index da75fc1d42..1c4239502e 100644
--- a/packages/backend/src/core/activitypub/misc/contexts.ts
+++ b/packages/backend/src/core/activitypub/misc/contexts.ts
@@ -564,6 +564,7 @@ const extension_context_definition = {
 	speakAsCat: 'firefish:speakAsCat',
 	// Sharkey
 	sharkey: 'https://joinsharkey.org/ns#',
+	hideOnlineStatus: 'sharkey:hideOnlineStatus',
 	backgroundUrl: 'sharkey:backgroundUrl',
 	listenbrainz: 'sharkey:listenbrainz',
 	// vcard
diff --git a/packages/backend/src/core/activitypub/models/ApPersonService.ts b/packages/backend/src/core/activitypub/models/ApPersonService.ts
index 598486cd84..2cb31b1f09 100644
--- a/packages/backend/src/core/activitypub/models/ApPersonService.ts
+++ b/packages/backend/src/core/activitypub/models/ApPersonService.ts
@@ -389,6 +389,8 @@ export class ApPersonService implements OnModuleInit {
 					movedToUri: person.movedTo,
 					movedAt: person.movedTo ? new Date() : null,
 					alsoKnownAs: person.alsoKnownAs,
+					// We use "!== false" to handle incorrect types, missing / null values, and "default to true" logic.
+					hideOnlineStatus: person.hideOnlineStatus !== false,
 					isExplorable: person.discoverable,
 					username: person.preferredUsername,
 					approved: true,
@@ -585,6 +587,8 @@ export class ApPersonService implements OnModuleInit {
 			isLocked: person.manuallyApprovesFollowers,
 			movedToUri: person.movedTo ?? null,
 			alsoKnownAs: person.alsoKnownAs ?? null,
+			// We use "!== false" to handle incorrect types, missing / null values, and "default to true" logic.
+			hideOnlineStatus: person.hideOnlineStatus !== false,
 			isExplorable: person.discoverable,
 			...(await this.resolveAvatarAndBanner(exist, person.icon, person.image, person.backgroundUrl).catch(() => ({}))),
 		} as Partial<MiRemoteUser> & Pick<MiRemoteUser, 'isBot' | 'isCat' | 'speakAsCat' | 'isLocked' | 'movedToUri' | 'alsoKnownAs' | 'isExplorable'>;
diff --git a/packages/backend/src/core/activitypub/type.ts b/packages/backend/src/core/activitypub/type.ts
index c9e20e0168..a0a5ae00dc 100644
--- a/packages/backend/src/core/activitypub/type.ts
+++ b/packages/backend/src/core/activitypub/type.ts
@@ -215,6 +215,7 @@ export interface IActor extends IObject {
 	};
 	'vcard:bday'?: string;
 	'vcard:Address'?: string;
+	hideOnlineStatus?: boolean;
 	noindex?: boolean;
 	listenbrainz?: string;
 	backgroundUrl?: string;