On television, Grant has guest starred on Sex and the City, Law & Order, Law & Order: Criminal Intent, Law & Order: Special Victims Unit, Damages, Supernatural and many other shows. She had the recurring roles in the ABC political drama Commander in Chief and Amazon political satire Alpha House. In film, she made her debut in the 1998 romantic comedy The Object of My Affection starring Jennifer Aniston, and the following years had supporting parts in films include Kinsey and When a Stranger Calls. She played Lauren Catuzzi Grandcolas in the 2006 biographical drama United 93, and appeared as Diane Sawyer in the 2008 historical drama Frost/Nixon. She also appeared in The Rebound (2009), Love & Other Drugs (2010), and Custody (2016).