Alyson Hannigan is an American actress best known to television audiences as Willow Rosenberg in Buffy the Vampire Slayer, for which she won a Teen Choice Award and a Saturn Award. She appeared in 144 episodes of the show, from 1997-2003.
She is also known for her starring role as Lily Aldrin in the sitcom How I Met Your Mother.
She also co-starred in the television series Free Spirit in 1989, appearing in 14 episodes.
Her other television credits include Touched by an Angel, Picket Fences, Veronica Mars, King of the Hill, That '70s Show, Angel: The Series and Roseanne.
Her feature film credits include American Pie, American Pie 2 (for which she won a Teen Choice Award), American Wedding, Beyond the City Limits, Dead Man on Campus and My Stepmother Is an Alien.
Hannigan was born in Washington, D.C. and raised in Atlanta. Currently she lives in Los Angeles.