Stars got dressed up to walk the carpet at tonight's Teen Choice Awards in LA. Taylor Swift showed some skin in a backless Maria Lucia Hohan, and Lea Michele looked sexy in a strapless dress. Nina Dobrev, in J. Mendel, and boyfriend Ian Somerhalder posed separately, while Ellen DeGeneres had Portia de Rossi before picking up the night's first surfboard. Justin Bieber celebrated girlfriend Selena Gomez's 20th birthday with her at the star-studded event as well.

Many of your other favorite celebrities stepped out for the night's festivities — click through the rest of the red-carpet snaps!

Robert Pattinson, Kristen Stewart, and Taylor Lautner took the stage at the Teen Choice Awards in LA last night to accept the ultimate choice prize for Breaking Dawn Part 1. The show dedicated a special segment to the film series, and presenter Zachary Levi gave a shout-out to Twilight already having won 41 Teen Choice Awards over the years. Both Kristen and Taylor thanked the fans for their unwavering support, and Robert, who was afraid of just repeating what the others said, managed to top them both — he passed his surfboard into the crowd! A group of excited girls latched on to accept Rob's board.

Ellen DeGeneres and her wife, Portia de Rossi, attended this evening's Teen Choice Awards in LA. The couple posed together on the carpet and also linked up with pal Taylor Swift for some pictures. Ellen was in the running for choice comedian, and she was surprised early in the show — Ellen won choice comedian and brought up her young friends, Nicki Minaj lovers Sophia Grace and Rosie, to help accept the honor.

Justin Bieber rocked white jeans on the carpet at this evening's Teen Choice Awards in LA. He's on hand as a nominee in multiple categories. He's in the running for choice male artist, choice Summer music star, choice fashion icon, choice male hottie, and choice twit, for his Twitter use. Two of his songs, "Boyfriend" and "Die in Your Arms," are up for respective choice single by a male artist and choice love song honors. Win or lose, it's a special day for Justin. It's his girlfriend Selena Gomez's 20th birthday, and they're getting to spend the evening today with pals like Carly Rae Jepsen. Justin's also due to take the stage as one of the show's performers.

Taylor Swift struck a sweet pose on the carpet at this evening's Teen Choice Awards in LA. Taylor wore a Maria Lucia Hohan LWD with a pair of Christian Louboutins. She attended to see if she's taking home any big honors this evening. Taylor's in the running in multiple categories, including choice female country artist, choice female artist, choice country song for "Sparks Fly," and choice single by a female artist for "Eyes Open." She's also recognized for her film work. Taylor's up for choice movie voice thanks to her role as Audrey in Dr. Seuss' The Lorax.

Selena Gomez hit the carpet at this evening's Teen Choice Awards in LA. She was pretty in pink in a cute Dsquared2 dress. Selena will soon find out if she's taking home any statues tonight. As part of Selena Gomez & The Scene, she's in the running for choice music group and choice single by a group for "Hit The Lights." Solo, Selena's up for choice female hottie. The day isn't just about awards for Selena — it's also her 20th birthday! We marked the occasion with a look at Selena Gomez and Justin Bieber's cutest moments.

Nina Dobrev wore J. Mendel to hit the red carpet at this evening's Teen Choice Awards in LA. She didn't pose with her real-life boyfriend, and The Vampire Diaries costar, Ian Somerhalder. Ian, though, was not too far away posing for pictures of his own. It's a big evening for Nina, Ian, and their series. They're up for individual honors in the categories of choice actor and actress in a fantasy or sci-fi show. Ian's also up for the coveted male hottie honor. There could be celebrating to do with their fellow leading man Paul Wesley if The Vampire Diaries beats Fringe, Once Upon a Time, Supernatural, and True Blood to win choice TV show: fantasy/sci-fi.

Lea Michele went strapless for this evening's Teen Choice Awards in LA. Lea tweeted a picture of herself getting ready with the help of her nail stylist Jenna Hipp, hairdresser Mark Townsend, and makeup artist Melanie Inglessis. Lea posed without her Glee costar, and real-life boyfriend, Cory Monteith. Both he and Lea could be winners, though, if their series wins this evening. Glee's up for numerous honors, including choice TV show comedy. Leo has an individual nod in the choice TV actress comedy category.

Gwen Stefani was on the red carpet at this evening's Teen Choice Awards in LA. She was accompanied by her No Doubt bandmates, Tony Kanal, Tom Dumont, and Adrian Young, before the show began. The group has been waiting for today's show, since it's the event where they'll make their live music debut ahead of their comeback album's September release. Gwen and the guys are expected on stage to perform their new song "Settle Down." The full record, Push and Shove, is out Sept. 25. What do you think of Gwen's ensemble? Make sure to check out our Teen Choice Awards fashion roundup.