Important: Outlook only lets you subscribe to a calendar on desktop. You can show or hide calendars you’ve already subscribed to, but you can’t subscribe to a calendar in the Outlook app on mobile devices. [source].
Learn how to subscribe to a calendar in Outlook on desktop.
Why are subscriptions that are added to Outlook desktop not appearing in my Outlook mobile app?
Outlook iOS app imports and show any subscription calendars that are added to Outlook Web Access, not Outlook desktop.
Add your OWA account in the app. If it was previously added, delete it and add it again to populate the existing calendar subscriptions.
I’ve deleted a calendar or group within Stanza. How do I remove it from my Outlook Calendar app?
You can only unsubscribe from a calendar on desktop.
How do I force refresh a calendar in my Outlook Calendar app on Mobile (iPhone and Android)?
Open the Outlook App
Launch the Outlook app on your mobile device.
Navigate to the Calendar
Tap on the Calendar icon located at the bottom of the screen.
Pull Down to Refresh
Place your finger near the top of the screen.
Swipe downwards to trigger a manual refresh.
A spinning circle or progress bar will appear, indicating that the calendar is syncing.
Wait for the Sync to Complete
Outlook will fetch the latest calendar data from your email server.