Rooney Mara, Katy Perry
Credit: Sharky / Splash News; Christopher Polk/Getty

The Super Bowl drew a star-studded crowd last night! We know who Rooney Mara was rooting for—her dad is a Giants VP!—but Katy Perry kept things neutral by working a half-Giants, half-Patriots jersey dress. See more stars who showed up to football's hottest event in the gallery, and tell us, who did you cheer for?