Lively is a cast member on TV's "Gossip Girl," who also appeared in the movies "The Town" and "The Sisterhood of the Traveling Pants."
Gosling's film credits include "The Notebook," "Lars and the Real Girl" and "Blue Valentine."
"They've been out a few times and are definitely into each other, but I don't think it's super serious or anything right now," one of Gosling's friends told E! "Yeah, they're casually dating, but I could see it becoming more. Ryan has been out with a few girls over the past couple of months."