I have not enabled alarms, but I still get them.

The macOS Calendar application can add its own alarms to events in subscribed calendars. To remove them, follow these instructions.

Step 1

Open the Calendar menu and select Preferences.


Open the Calendar menu and select Preferences.
Step 2

Select the account where the subscribed calendars are (usually iCloud or On My Mac). Make sure both Events and All Day Events are set to None.


Select the account where the subscribed calendars are (usually iCloud or On My Mac). Make sure both Events and All Day Events are set to None.