The former The OC star and her longtime beau Hayden Christensen are expecting their first child together.
"They've both talked about this for a while and are so excited," a source told Us Weekly. "Everyone is beyond thrilled for them."
The 32-year-old Hart of Dixie actress spoke about her desire to be a mom in a May 2013 interview with Cosmopolitan, telling the magazine that: "Having kids is something I want to see in my future -- I hope."
Bilson and Christensen meet on the 2007 set of the film Jumper where they played star-crossed lovers. The couple got engaged in 2008 and separated for three months in 2010 before getting back together.