Channing gained notoriety portraying a murderer in the 1973 made-for-TV movie The Girl Most Likely to ...; her first starring feature role came in 1975 playing opposite Jack Nicholson in The Fortune. In 1978, Channing landed the part of tough-talking teen Betty Rizzo in the silver-screen version of Grease. Her other film credits include Without a Trace (1983), Heartburn (1986) and 1993's Six Degrees of Separation, for which she received Oscar and Golden Globe nominations.
Channing joined the cast of the TV drama "The West Wing" in 1999, winning an Emmy for the part in 2002. She added another Emmy nod to her résumé in 2006 for her leading role in the sitcom "Out of Practice."