I have a Facebook Events calendar in Google Calendar, but the Calendar app won't synchronize it. It will sync all the other calendars like Meetup, ZipCar, etc, but not Facebook. The Facebook calendar won't even show up in the phone. I disconnected the account and re-connected it again but it still fails to show up. It does show up in the Google Calendar web page.
iOS 10.3.2, iPhone 5
Best Answer
Had to go to https://calendar.google.com/calendar/syncselect and select Facebook Events.
https://support.google.com/calendar/answer/99358?hl=en&ref_topic=3417927