Alyson Lee Hannigan (born March 24, 1974) is an American actress and television presenter. She is best known for her roles as Willow Rosenberg in the television series Buffy the Vampire Slayer (1997–2003), as Lily Aldrin in the sitcom How I Met Your Mother (2005–2014) for which she won a People's Choice Award in 2009, and as Michelle Flaherty in the American Pie film series (1999–2012). Since 2016, Hannigan has hosted the television show Penn & Teller: Fool Us. She also provides the voice of Claire Clancy in the Disney Junior animated series Fancy Nancy (2018–present).

Filmography

• 2026Solo Mio — Meghan
• 2023Office Race — Pat
• Doogie Kamealoha, M.D. — Dawn
• 2021Flora & Ulysses — Phyllis
• Outmatched — Beth
• 2019Abducted: The Mary Stauffer Story — Mary Stauffer
• Fancy Nancy: Fancy It Yourself — Nancy
• 2019Kim Possible — Dr. Ann Possible
• 2019You Might Be the Killer — Chuck
• Fancy Nancy — Claire Clancy (voice)
• 2018Man of the House — Jessie
• 2017Do You Take This Man — Rachael
• Star Plates
• Sofia the First — (voice)
• 2012American Reunion — Michelle Levenstein
• 2011Love, Wedding, Marriage — Courtney
• Penn & Teller: Fool Us — Self - Host, Producer
• The Goode Family
• Buffy the Animated Series — Willow Rosenberg
• 2006Date Movie — Julia Jones
• 2006Farce of the Penguins — Hottie Penguin (voice)
• American Dad! — Lexie (voice), Ugly Stepsister #2 (voice), Chelsea (voice)
• How I Met Your Mother — Lily Aldrin
• Robot Chicken — Steelheart (voice)
• 2004American Pie: Revealed — Self, Thanks
• Veronica Mars — Trina Echolls
• 2003American Wedding — Michelle Flaherty
• 2001American Pie 2 — Michelle Flaherty
• 2001Beyond the City Limits — Lexi
• 2000Boys and Girls — Betty
• 100 Deeds for Eddie McDowd
• 1999American Pie — Michelle Flaherty
• Angel — Willow Rosenberg
• 1999Hayley Wagner, Star — Jenna Jakes
• 1998Dead Man on Campus — Lucy
• That '70s Show — Suzy Simpson
• The Wild Thornberrys — Gerda (voice)
• Buffy the Vampire Slayer — Willow Rosenberg
• King of the Hill — Stacey Gibson (voice)
• 1996A Case for Life — Iris
• 1996For My Daughter's Honor — Kelly
• TFI Friday
• 1995The Stranger Beside Me — Dana
• Touched by an Angel — Cassie Peters
• Picket Fences — Peggy Patterson
• The Tonight Show with Jay Leno
• Rugrats — Cynthia P.I. (voice)
• The Torkelsons — Samantha
• Free Spirit — Jessie Harper
• The Simpsons — Melody Juniper (voice)
• 1988My Stepmother Is an Alien — Jessie Mills
• Roseanne
• 1986Impure Thoughts — Patty Stubbs
• Dodie & Cheryl Get Hitched — Cheryl Crum

Appearances as themselves (28)

• Dancing with the Stars Official Podcast — Self
• Adorableness — Self
• Girl Scout Cookie Championship — Self - Host
• Outrageous Pumpkins — Self - Host
• The Kelly Clarkson Show — Self
• The Gong Show — Self - Judge
• The $100,000 Pyramid — Self
• Beat Bobby Flay — Self
• Hollywood Game Night — Self
• 2011More Business of Being Born — Self [Part 2,3]
• Watch What Happens Live with Andy Cohen — Self - Guest
• The Bonnie Hunt Show — Self
• I Love the '70s: Volume 2 — Self
• The Megan Mullally Show — Self - Guest
• Dancing with the Stars — Self - Contestant, Self - Audience Member, Self - Rehearsal Visitor
• The Reichen Show — Self
• Jimmy Kimmel Live! — Self - Guest
• Pepsi Smash — Self - Host
• The Ellen DeGeneres Show — Self
• 2001Playboy Mansion Parties Uncensored — Self
• Teen Choice Awards — Self
• The Late Late Show with Craig Kilborn — Self - Guest
• The Daily Show — Self - Guest
• Late Night with Conan O'Brien — Self - Guest
• Late Show with David Letterman — Self - Guest, Self - Top Ten Presenter
• MTV Movie & TV Awards — Self - Presenter
• Entertainment Tonight — Self
• American Pie: Beneath the Crust Vol. 2 — Self