Alyson Hannigan acted as Willow Rosenberg in the Buffy the Vampire Slayer series .
She is best known for her roles as Willow Rosenberg on the television series Buffy the Vampire Slayer ( 1997–2003 ) , Willow Rosenberg on the television series Buffy the Vampire Slayer ( 1997–2003 ) Willow Rosenberg on the television series Buffy the Vampire Slayer ( 1997–2003 ) .
Alyson Hannigan