=== Tv ===
{| class="wikitable sortable"
|-
! Year
! Title
! Role
! class="unsortable" | Notes
|-
| 1989–90
| ''[[Free Spirit (TV series)|Free Spirit]]''
| Jessie Harper
| Fast rolle, 14 afsnit
|-
| 1990
| ''[[Roseanne]]''
| Jan
| Afsnit: "Like, a New Job"
|-
| 1991
| ''[[Switched at Birth (1991 film)|Switched at Birth]]''
| Gina Twigg  (13–16 år)
| Tv-film
|-
| 1993
| ''[[The Torkelsons/Almost Home|Almost Home]]''
| Samantha
| 2 afsnit
|-
| 1994
| ''[[En engel ved min side|Touched by an Angel]]''
| Cassie Peters
| Afsnit: "Cassie's Choice"
|-
| 1995
| ''[[The Stranger Beside Me (film)|The Stranger Beside Me]]''
| Dana
| Tv-film
|-
| 1996
| ''[[For My Daughter's Honor]]''
| Kelly
| Tv-film
|-
| 1996
| ''[[Picket Fences]]''
| Peggy Patterson
| Afsnit: "To Forgive Is Divine"
|-
| 1997–2003
| ''[[Buffy the Vampire Slayer]]''
| Willow Rosenberg
| Fast rolle, 144 afsnit
|-
| 1999–2000
| ''[[100 Deeds for Eddie McDowd]]''
| Gigi (stemme)
| 3 afsnit
|-
| 2000
| ''[[En vild familie|The Wild Thornberrys]]''
| Gerda (stemme)
| Afsnit: "Every Little Bit Alps"
|-
| 2001–03
| ''[[Angel (tv-serie)|Angel]]''
| Willow Rosenberg
| 3 afsnit
|-
| 2002–03
| ''[[Rollinger (tv-serie)|Rugrats]]''
| Cynthia P.I. / Ung Starlet (stemme)
| 2 afsnit
|-
| 2004
| ''[[That '70s Show]]''
| Suzy Simpson
| 2 afsnit
|-
| 2004
| ''[[King of the Hill]]''
| Stacey Gibson (stemmee)
| Afsnit: "Talking Shop"
|-
| 2005
| ''[[Veronica Mars]]''
| Trina Echolls
| 3 afsnit
|-
| 2005–14
| ''[[How I Met Your Mother]]''
| [[Lily Aldrin]]
| Fast rolle, 206 afsnit
|-
| 2009
| ''[[The Goode Family]]''
| Michelle (stemme)
| Afsnit: "Graffiti in Greenville"
|-
| 2011
| ''[[The Simpsons]]''
| Melody (stemme)
| Afsnit: "[[Flaming Moe]]"
|-
| 2011, 2018
| ''[[Robot Chicken]]''
| Forskellige stemmer
| 2 afsnit
|-
| 2011, 2013
| ''[[American Dad!]]''
| Chelsea / Peasant's datter (stemme)
| 2 afsnit
|-
| 2014
| ''[[Sofia the First]]''
| Winter (stemme)
| Afsnit: "Winter's Gift"
|-
| 2014
| ''[[The McCarthys]]''
| Pam
| Afsnit: "Red Sox Swap"
|-
| 2016–present
| ''[[Penn & Teller: Fool Us]]''
| Sig selv (vært)
| 64 afsnit
|-
| 2018–present
| ''[[Fancy Nancy (TV series)|Fancy Nancy]]''
| Claire Clancy (stemme)
| Fast rolle, 26 afsnit
|-
| 2019
| ''[[Kim Possible (film)|Kim Possible]]''
| Ann Possible
| Tv-film
|-
| 2019
| ''[[Pure (Canadian TV series)|Pure]]''
| Esther Dunkel
| 2 afsnit
|-
| 2019
| ''[[Abducted: The Mary Stauffer Story]]''
| Mary Stauffer
| Tv-film<ref>{{Cite web|url=https://deadline.com/2019/04/lifetime-orders-abduction-of-mary-stauffer-movie-starring-alyson-hannigan-saving-alex-1202587289/|title=Lifetime Orders 2 Movies: 'Abduction Of Mary Stauffer' Starring Alyson Hannigan & 'Saving Alex'|first=Denise|last=Petski|date=3. april 2019|website=Deadline}}</ref>
|-
| 2020
| ''[[Girl Scout Cookie Championship]]''
| Sig selv (vært)
| 4 afsnit
|-
| 2020
| ''[[Outmatched]]''
| Annabeth
| Afsnit: "Couple's Friends"
|-
| 2021
| ''[[Adorableness (TV series)|Adorableness]]''
| Sig selv
| Panelist<ref>{{cite web|last=Ossad|first=Jordana|title=MTV is About to Get a Dose of Adorableness|url=https://www.mtv.com/news/3178380/mtv-new-comedy-show-adorableness/|work=[[MTV]]|date=21. juni 2021}}</ref>
|}
Levende_personer