It was only natural for Adam Levine to ask his childhood best friend Jonah Hill to officiate at his July 2014 wedding to model Behati Prinsloo.
After introducing her publicist to "Zombieland" director Ruben Fleischer, Stone was asked to officiate at the November 2012 wedding.
Singer Vanessa Carlton and Deer Tick singer-guitarist John McCauley weren't the only famous faces at their 2013 wedding. The couple asked Feetwood Mac's Stevie Nicks to officiate and she obliged! Carlton is now expecting the couple's first child. Click here to see her growing baby bump.
Former onscreen father and daughter crime-fighting duo Victor Garber and Jennifer Garner didn't always get along. But in real life, the "Alias" costars were best of friends. Garber even officiated at Garner's wedding to Ben Affleck.
The "Vampire Diaries" star officiated at his pals' wedding in Georgia. Click here to watch the video but first make sure you have a box of tissues at hand!
When a couple's officiant canceled, Segal stepped in and married them live on The Tonight Show with Jay Leno in 2010.
The TV show host married his costume designer Scott Cronick and his partner David Gorshein on his show. Watch the video here.
Lady Gaga married one her best friends when gay marriage was legalized in New York. "I'm actually getting ready to marry one of my best friends," Lady Gaga told Perez Hilton.
Being a knight has some perks. Sir Ian McKellen was asked to officiate his famous pal Patrick Stewart's wedding to Sunny Ozell.
These stars' most important role: Wedding officiate.