Apple Calendar not syncing with Google Calendar

For me the issue was a changed google password.

Go to iOS Settings -> Calendar -> Accounts -> Gmail, check if there's an error there with a prompt to re-login. After login with the new password iOS -> Google Calendar sync works immediately, Google Calendar -> iOS takes up to 10 mins.

This worked!

From iPhone: Go to Google Calendar > Select your profile (the coloured circle with your initial in the upper right corner) > Manage accounts on this device > iCloud will appear in the list (noted as a 'system account') > make sure the toggle in ON

This worked for me ... to solve problem iCal (phone) not syncing To Google Cal (but other way works)

1. Create event in Apple cal … in the Event Details the option Calendar needs to be set to my - gmail address.
2. 5 secs later it appears in Google Cal PC - problem solved ... but now need to ...
3. Set the default Calendar to this, ie gmail address.
4. On phone Apple iPhone > settings > calendar > default Calendar - set to my gmail.com address
5. Solved !

Setting my Apple Cal default cal was easy ... iPhone > settings >calendar>default calendar - my gmail address

PROBLEM FIXED

Although this suggestion didn’t work for me, here’s what did seem to work: When I create an event on my Apple (phone) calendar, it seemed to be defaulting to one of several calendars in the event itself (my gmail address or in iCloud, Google or Calendar). If I select iPhone calendar, it does synch. I don’t know where to set the default, but after I started changing this on all events, now it is defaulting to this calendar, and everything is synching now. I don’t understand it, but it’s working.

Privacy and security>Calendars>Google Calendar>Full Access

Yes this worked ... I went into the event created on Apple Cal(phone) - under Calendar I selected my gmail address and 5 sec later bingo in PC Google Calendar. Now I just need to work out how to set this as default ??

Thank you so much for this - I've spent hours trying to figure this out, and your suggestion is the only thing that worked for me. I changed the settings in my Apple calendar to only show events that had been categorized under "iCloud -> Calendar" and then individually had to change those to my Gmail account. It was tedious, but at least it worked when none of the other suggestions did.

For me, the simple solution was to always be sure when I add an event on my phone, that I select iPhone Calendar for the event (with a yellow bar). That seemed to fix it.

Yes - See my 2 replies under bfirth .... set default Calendar to your Gmail address

Is full access switched on in settings > Google calendar as well as in privacy settings?

This is a very unsatisfying answer...but just wait 15-20min and then check your Google Calendar again (in browser and/or in iPhone app). In past years the situation used to be much worse (calendar events added to a Google Calendar via a Mac/iPhone app never showing up in Google Calendar app/browser)...but for me it commonly now just takes awhile.

Leaving the Calendar app open on Mac/iPhone (where the added event can be seen just fine) might help...or maybe that's just superstition, and waiting is all we need to do. Which implies a periodic but non-immediate server update/push, somewhere between Apple and Google, not a software bug.

in the Google calandar if you check your accounts there is a place to add the iCloud account and it fixed my calandar !

I just updated to iOS 16.7.1. I am wondering if this is what has caused the two calendars, iPhone and Google, to no longer sync. Also, when I search for keywords on the iCalendar, it can't find the entries. If I go to the exact date, the entries are there exactly as I remembered.