Rachel Sarah Bilson, born August 25, 1981, in Los Angeles, California, is an American actress whose career took off with her breakout role on television during the early 2000s.

Daughter of writer-director-producer Danny Bilson and sex therapist Janice Stango, she grew up in a show business family with Ashkenazi Jewish and Italian heritage, attending Notre Dame High School where she participated in theater productions before briefly studying at Grossmont College and pursuing acting full-time.

Rachel Bilson debuted on screen in small roles on Buffy the Vampire Slayer and 8 Simple Rules in 2003, but her casting as the initially minor character Summer Roberts on Fox's The O.C. transformed her into a star, as the role expanded into a series regular whose romance with Seth Cohen became central to the show's success from 2003 to 2007.​

Following The O.C., she transitioned to film with her debut in The Last Kiss in 2006 opposite Zach Braff, earning a Teen Choice Award nomination, and starred as Millie Harris in the science-fiction action movie Jumper in 2008 alongside Hayden Christensen, with whom she began a high-profile relationship. 

She appeared in ensemble projects like New York, I Love You in 2009 and indie romances such as Waiting for Forever in 2011 and Life Happens in the same year, while guesting on shows including How I Met Your Mother as Cindy across multiple seasons.

In 2011, she landed the lead role of Dr. Zoe Hart, a New York physician relocating to rural Alabama, on The CW's Hart of Dixie, created by her former O.C. collaborator Josh Schwartz, running for four seasons until 2015 and earning her another Teen Choice nomination.​

Rachel Bilson continued with recurring roles like Alyssa Greene on Nashville in 2017, reuniting with O.C. co-star Chris Carmack, and Sam Swift on ABC's Take Two in 2018, alongside guest spots on Drunk History and a dramatic turn as Alison on Accused in 2023.

Her film work includes The To Do List in 2013 and American Heist in 2014, often blending comedy and drama in supporting capacities. Rachel Bilson shares a daughter, Briar Rose, born in 2014, with ex-partner Christensen, and has been vocal about fashion, launching a shoe line called Blake Belladonna while maintaining a presence in podcasts and social media.​