The stars were out last night (Sun. May 22) at the 2011 Billboard Music Awards!

Among the many celebs who walked the white carpet outside the MGM Grand Arena in Las Vegas were Rihanna, Nicki Minaj, Taylor Swift, Kelly Rowland, Michelle Williams, Trey Songz, Keri Hilson and Ne-Yo.

Check out 25+ pics from the red carpet below: