Jason Jordan Segel is an American actor and writer. He is best known for his role as Marshall Eriksen in the CBS sitcom How I Met Your Mother from 2005 to 2014. He began his career with director and producer Judd Apatow on the television series Freaks and Geeks (1999–2000) and Undeclared (2001–2002) before gaining prominence for his leading roles in various successful comedy films in which he has starred, written, and produced.