How to delete spam meetings on calendar

Those options you provided only show for an event invitation. If there is only one, you should be able to Decline it. But if there are multiple or are recurring, they are likely coming from a spam calendar you have signed up for in which you would need to delete the entire thing. As long as you keep declining the events they will just keep sending them back. Go to Settings > Apps > Calendar > Calendar Accounts > Tap the unknown account and then Delete Account.

I've had the same thing. For the person who said 'we have no idea what you're talking about' it's quite simple - an unwanted, unsolicited, 'spam' calendar invitation appears in your Apple Calendar app, asking you to Accept, Decline or Maybe, without apparently there being an equivalent email with the invitation in Mail.

Eventually I worked out that there was an email - I just couldn't see it because I had blocked it and reported the sender as spam in Apple Mail months ago. Somehow Mail was still seeing the invitation and offering it in Calendar. Seems an odd logic to do that from blocked senders but whatever. Deleting that email should remove it, but that presumably won't stop the next one.

So once I worked that out, I found another option. Similar to the reply here that mentioned MS accounts, my email was to a Gmail account which I sync to in Mail. If that also applies, you need to open the invitation in Google Calendar. If you right click on it, you have the option there to report that as Spam. Doing that deletes it from Google and it will delete from Mac when you sync your Apple Calendar. Hopefully that stops it showing up again in the future from other emails from that sender. Time will tell.

I assume you could do that in Gmail as well, to block at source, but blocking in Apple Mail has always worked for me before - no insight into why this one account (and it is only one) gets through. And before anyone says it, no I haven't subscribed to anything - this is just junk email.

Are you using a Microsoft Exchange, Outlook, or Hotmail email account?

I only ask because Microsoft servers have been inundated with calendar spam invites that will show up in your Calendar app if you are syncing those account to the Calendar. You can quit syncing those account with the calendar at Settings > Calendar > Accounts, and those spam invites will go away.

We have no idea what you are talking about. What are “spam meetings”? Where did they come from? Calendar events do not add themselves.

Please explain in detail what you are experiencing.