Who can see the Facebook events I'm interested in or going to?

People may be able to see if you're interested or going to an event depending on the event's privacy settings. You can also save an event to keep your interest in an event private.
Public Events
If it's a public event, only friends and hosts can see if you're interested or going. They may see your status in a News Feed post, notification, on the Event page itself or in the Events section of your profile. You can control the visibility of your response on the Event page.
Private Events
If it's a private event, everyone invited to the event is able to see if you're going. People who aren’t invited can’t view who’s attending, the event description, event discussion, photos or videos.
Save an Event
If you want to keep your interest in an event private, you can save it:
  1. From your News feed, click Events in the left menu. You may have to click See More first.
  2. Click the event and then click More below the event's title.
  3. Select Save.
Events you've saved are listed below your upcoming events.