Marissa Cooper returns!
Mischa Barton was all smiles lounging in a beach chair in Miami, Fla. on Tuesday.
PHOTOS: Most talked-about bodies of 2011
And why not? The sometimes-troubled star, 25, looked the slimmest she has since her days as the buzzed-about star of The OC. Clad in a skimpy two-piece bikini, Barton grinned from ear-to-ear behind her sunglasses, showing off taut abs and more.
PHOTOS: Mischa and other celebs' nip slips
Barton, whose weight has fluctuated since her heyday, recently wrapped filming her role as the beautiful love interest in the flick The Misadventures of Ben Blanks.
She checked into a psychiatric hospital in 2009, and opened up about her battle with depression in fall 2010.
PHOTOS: Mischa's battle with her ex
Tell Us: How do you think Barton looks these days?
Get more Us! Follow us on Twitter, Friend us on Facebook, Subscribe to Us Weekly
Chrissy Teigen, Katy Perry and Lady Gaga spotlight their pooches on today's Celeb Gone Social.
Selena Gomez celebrates her birthday early with a helicopter ride in Italy with new pal Cara Delevingne on today's Celebs Gone Social.
Find out where the cast from "When Harry Met Sally" is today.
See some of the cutest moments from Prince George's first year.
Gwen Stefani shares photos from behind the scenes of a photo shoot for her Harajuku brand on today's Celebs Gone Social.
Let's check out some of Eva's tactics behind her baby bump secret on Replay hosted by Wonderwall's Kirby Kristen.
© 2014 Microsoft