Hi, Claudia Monte
Good day.
Thank you for posting to the Microsoft Community. We are glad to assist you.
According to your description, to fix the issue of iPhone calendar not syncing with Outlook calendar, please follow these steps:
- Check if your iPhone is connected to the internet and if the Outlook app is up to date.
- Make sure that you have enabled the option to sync your calendar in the Outlook app on your iPhone. To do this, go to Settings > Passwords & Accounts > Outlook > toggle on the switch for Calendars.
- Check if the events you added on your iPhone are saved to the correct calendar. Sometimes, events may be saved to a different calendar, which may cause syncing issues.
- If the above steps do not work, try removing and re-adding your Outlook account on your iPhone. To do this, go to Settings > Passwords & Accounts > Outlook > Delete Account. Then, add your account again by going to Settings > Passwords & Accounts > Add Account > Outlook.
If the issue persists, would you please be kindly to refer Outlook for iOS dedicating team as below:
Outlook for iOS
Tap your profile photo and then the ? > Contact Support.



Thanks in advance for your understanding! Your patience and cooperation will be highly appreciated. Hope you all the best!
Best regards,
Microsoft Community Moderator.