Celebs are giving back in an oh-so stylish way.

Actress Kate Mara recently donated some fashions from her closet at Calypso St. Barth in SoHo during the boutique's Calypso Cares event, benefitting the nonprofit Clothes4Souls. We're told that Mara brought in multiple sweaters and dresses, and then bought a pair of jeans and some T-shirts.

Meanwhile, on the West Coast, Sarah Michelle Gellar donated "a ton" of clothes at the Calypso in Brentwood, California, then left the store with new items for herself and her daughter.

Celebrity or not, shoppers who donate during the drive, which runs through May 20, receive 20% off their purchase.