"Leelee delivered a bouncing, healthy girl late last night in New York City," her representative told Usmagazine.com. "Proud father is her fiance, menswear designer Adam Kimmel."
The child, whose name was not announced, is the first for the couple.
Sobieski's movie credits include "Public Enemies," "Eyes Wide Shut," "Here on Earth," "The Glass House" and "A Soldier's Daughter Never Cries."
Swim Week Miami Beach 2014 [PHOTOS]