The main cast of "How I Met Your Mother" includes:

• Josh Radnor as Ted Mosby
• Jason Segel as Marshall Eriksen
• Cobie Smulders as Robin Scherbatsky
• Neil Patrick Harris as Barney Stinson
• Alyson Hannigan as Lily Aldrin
• Cristin Milioti as Tracy McConnell (the Mother)

The show also features Bob Saget as the narrator (Older Ted Mosby). These actors played the core characters throughout the series which aired from 2005 to 2014.