Josh Radnor Ted Mosby Actor Jason Segel Marshall Erikson Actor Alyson Hannigan Lily Aldrin Actor Neil Patrick Harris Barney Stinson Actor Cobie Smulders Robin Sherbatsky Actor Bob Saget Narrator David Henrie Son Guest Star Lyndsy Fonseca Daughter Guest Star Joe Nieves Carl Guest Star Camryn Manheim Ellen Pierce Guest Star Beth Lacke Dr. Sarah O'Brien Guest Star Nick Jaine Sudeep Guest Star Carter Bays Executive Producer Craig Thomas Executive Producer Pamela Fryman Director Sam Johnson Writer Chris Marcil Writer