Sarah Lancaster (born February 12, 1980) is an American actress. She is known for her long-running roles as Rachel Meyers in the NBC series Saved by the Bell: The New Class and Ellie Bartowski in the NBC comedy-spy series Chuck, as well as playing Chloe Grefe in Lovers Lane, Madison Kellner on The WB's Everwood, and Marjorie in ABC's TV series What About Brian.
Lancaster has appeared on Sabrina, the Teenage Witch, Dawson's Creek, That '70s Show, Scrubs, and CSI: Crime Scene Investigation. She also landed two recurring roles: on The WB series, Everwood, as Ephram's love interest Madison Kellner; and on David E. Kelley's FOX series, Boston Public. In 2005 she starred in the TV movie Living With the Enemy. Most notably, she appeared as Ellie Bartowski Woodcomb on the NBC series Chuck from 2007 to 2012.
Lancaster has also worked as a jealous girlfriend-turned-serial killer in the movie Lovers Lane, and as the blackjack dealer, Veronica Harold, on CBS's short-lived Dr. Vegas.