The shared calendar that you add to your smartphone must already be shared with you that you will be able to view using Outlook desktop client or web client.
- Open your Outlook app on your smartphone. If you do not have the Outlook app, please download the app and follow the steps below.
- Switch to your calendars in Outlook for iOS.
- Open the the calendar menu.
- Tap the add calendar button.
- Tap Add Shared Calendars.
- Search for the person or group whose calendar you already have permission to access
- Tap the add button next to their name.
- The calendar will appear in your list.