Be completely honest: If you could have anybody officiate your wedding, wouldn't it be a celebrity? Can't you just imagine Beyoncé saying, "By the power vested in me..." and then bursting out in "Halo"?
Sadly, we can't all be Stanford and Anthony on Sex and the City, where Liza Minnelli just "manifests" and then does the Single Ladies dance at the reception. But celebs (who are just like us, duh) do attend — and sometimes even crash — weddings, act as bridesmaids, and even officiate their friends' weddings from time to time.
Lady Gaga got ordained after gay marriage was legalized in New York state. Emma Stone played matchmaker. And Kris Jenner? Well, she was kind of born to be a wedding officiant.