How to sync an Outlook calendar to iCloud on a Mac

Outlook and iCloud don't sync with each other, so there's no setting that puts Outlook events into an iCloud calendar. On a Mac, you can keep an iCloud calendar filled with copies of your Outlook events, and iCloud then carries them to your iPhone, iPad and Apple Watch.

Why Outlook and iCloud don't share

An Outlook calendar lives on a Microsoft server: Exchange or Microsoft 365 for work accounts, Outlook.com for personal ones. An iCloud calendar lives on Apple's servers. Each service syncs its own events to your devices, and nothing else.

Apple Calendar on your Mac can show both side by side, but that only changes what you see on that Mac. The Outlook events stay in the Outlook account, so they only appear on devices where that account is set up. For a work account, that might be just your Mac: the server may only be reachable over a VPN, or your company may not support it on personal devices.

The built-in options

Publish the Outlook calendar and subscribe to it

Outlook on the web can publish a calendar as a link, in Settings › Calendar › Shared calendars › Publish a calendar. Add that link to Apple Calendar with File › New Calendar Subscription, and choose iCloud as the location so it reaches your other devices. It works, with limits:

• It's read-only. You see the events, but you can't change them.
• It isn't live. A subscribed calendar refreshes on a schedule, so changes can take a while to show up.
• You pick one detail level for the link: busy times only, titles and locations, or all details. Anyone who has the link can see the calendar.
• Many organizations turn publishing off, so a work account may not offer it.

Export and import

You can export Outlook events to an .ics file and import it into an iCloud calendar. That's a one-time copy: meetings added or moved afterwards don't follow.

A note on the new Outlook for Mac

The new Outlook for Mac keeps its calendars in its own store, which other apps can't read. Add the account in System Settings › Internet Accounts as well, so its calendars show up in Apple Calendar and in apps like Syncom. Classic Outlook is different: Syncom can list its calendars directly while Outlook is open, and checks them every few minutes.

How to do it with Syncom

Syncom is a Mac menu bar app that copies events between any calendars your Mac can see, and keeps the copies up to date. It syncs when a calendar changes, when your Mac wakes and when your VPN connects, with a safety-net sync every 5 minutes to 2 hours.

1. 1
   Add your accounts to your Mac. In System Settings › Internet Accounts, add your Outlook account (choose Microsoft Exchange) and make sure Calendars is on for iCloud.
2. 2
   Add a sync. From Syncom in the menu bar, add a sync. Pick the Outlook calendar on one side and an iCloud calendar on the other, and set the direction from Outlook to iCloud.
3. 3
   Choose what copies show. Start from a preset: Full mirror copies everything, Title & time only leaves out location and notes, and Busy blocks only shows just the time, under a title you choose. Then leave it running.

A one-way sync never edits or deletes your Outlook events. Only its copies in iCloud change. Recurring meetings copy correctly, and if one meeting in a series moves, only that copy moves. Tag an event #nosync in its title or notes to keep it out.

Syncom syncs while your Mac is on and you're logged in, so changes reach iCloud whenever your Mac is awake. Copying a work calendar to a personal account? Company policies vary, so check yours first. The Busy blocks only preset shares just the times.