Lily Aldrin is a fictional character in the CBS television series How I Met Your Mother.
Lily is portrayed by American actress Alyson Hannigan. She is the wife of Marshall Eriksen and the best friend of Ted Mosby, Robin Scherbatsky and Barney Stinson. Lily is a kindergarten teacher and an amateur painter. In the eighth season, she gets a job as an art consultant.
Lily is also the only member of the original main cast of the series who has not appeared in every episode, due to Alyson Hannigan taking leave after giving birth to her first child.