Theron has been spotted at multiple UFC events over the years, but putting her over the top on this list is an interview she did with Conan O'Brien, claiming she was "obsessed" with the fights. Not too shabby for the UFC to have an Academy Award winner among its staunchest of followers.
On big fight nights, the former Disney star's young, female demographic must have no idea what she's talking about on social media. The "Really Don't Care" singer was spotted at UFC cheering for Chris Weidman and Ronda Rousey. Weidman recently returned the favor by attending one of her concerts. Lovato has grown up quite a bit since getting her start on "Barney & Friends."
Getty ImagesEthan Miller
Georges St-Pierre has a funny story about fighting in the Octagon and looking out into the crowd and laying eyes on the most beautiful woman he has ever seen. That was Crawford, who was a regular at UFC events in the mid-2000s and beyond. The supermodel. Crawford even once got her chest signed by Hall of Famer Matt Hughes. Now that's dedication to fandom.
The singer and actress was once tied to a romance with former UFC welterweight champion Georges St-Pierre. UFC president Dana White allegedly introduced the two, but both have denied ever having a relationship. Moore is married now, but she remains a big fan of the fights. Just two years ago, the Culinary Union, the organization trying to keep the UFC out of New York, attacked her for having ties to the organization.
Spencer Pratt and Heidi Montag
The UFC is like a date night for "Speidi." The married former "The Hills" stars have been fans for years. Pratt actually trains himself and not long ago proclaimed that he would one day step into the UFC Octagon. Pratt is a close friend of UFC middleweight and Ultimate Fighter alum Kevin Casey. The two even did a rap video together. Or something.
Getty ImagesEthan Miller
Who would expect the uber-cultured television chef and author to get excited about guys fighting each other in a cage? Well, Bourdain got into the UFC the way many man get into a lot of things -- because of a woman. Bourdain's wife Ottavia trains in Brazilian jiu-jitsu at Renzo Gracie's academy in New York City. And now Bourdain himself is training. Both are often spotted attending UFC events.
WireImageMichael N. Todaro
Al Bundy? For real? Oh yeah. Believe it or not, O'Neill is a black belt in Brazilian jiu-jitsu under Rorion Gracie. He has been practicing the martial art for more than 20 years and once called receiving his black belt the second greatest accomplishment in his life after the birth of his children. The "Modern Family" star continues to train regularly and is an avid watcher of the UFC.
Getty ImagesTibrina Hobson
Jonny Lee Miller
Yes, Sherlock Holmes loves him some MMA. Miller has been spotted at UFC events now for more than a decade. His allegiance goes away back -- long before he starred alongside Lucy Liu in the CBS hit "Elementary." Miller isn't just a fan who tunes in for the big fights, either. You can find him tweeting about FOX Sports 1 cards as well. He's a massive fan.
Getty ImagesChance Yeh
We're not entirely sure how much O'Donnell watches the UFC on the regular. But when Urijah Faber is fighting, the former talk show host and comedienne almost always has a front-row seat. O'Donnell has a little crush on the former WEC featherweight champion and has had him on her shows. The two have become friends. Faber even gave Rosie a little smooch before his fight with Eddie Wineland in 2011.
Zuffa LLC via Getty ImagesMike Roach/Zuffa LLC
The "Newsroom" star is a massive UFC fan and close friend of UFC president Dana White. Two years ago, White posted a picture of him and Munn out partying the night the UFC 146 main event got cancelled due to Alistair Overeem's positive drug test. Munn wrote back that White was her "brother" and she loved him. Aww.