Jason Morgan Ritter (born February 17, 1980) is an American actor, and the son of actress Nancy Morgan and late actor John Ritter, known for his roles as Kevin Girardi in the television series Joan of Arcadia, as Sean Walker in the NBC series The Event, and as the voice of Dipper Pines in Gravity Falls. He also played the recurring role of Mark Cyr in the NBC television series Parenthood, for which he received an Emmy Award nomination.