Your Google account may be set to automatically add events related to Gmail to Google Calendar.
If you want to stop Gmail from automatically adding events to Google Calendar, you need to turn off the connection between Gmail and Google Calendar.
Here is how to turn it off.
- Open the Gmail website on a PC or similar device
- Click the gear icon in Gmail
- Click "See all settings"
- On the Settings screen, scroll down and turn off the smart features option ("Smart features in Google Workspace")
- Open the Google Calendar website
- Click the gear icon in Google Calendar
- Click Settings
- Under "Events from Gmail", turn off "Show events from Gmail"
Notes on turning off the connection
When you turn off the connection between Google Calendar and Gmail, all events that were added to Google Calendar from Gmail are deleted. Existing event data created this way will also disappear, so please be careful.