Teresa Gallagher is an American-born British voice actress for The Amazing World of Gumball. She is the voice of Nicole, Penny, Mrs. Robinson, Jackie, Teri, Penny's Sister, the School Nurse, Siciliana, and Chi Chi's mother.
- Lapitch the Little Shoemaker (Lapitch, Perwinkle Percival III)
- Mama Mirabelle's Home Movies (Karla the Zebra, 2007-2017)
- The Pinky and Perky Show (KT, 2008-2009)
- Thomas the Tank Engine & Friends (Emily, Rosie, Mavis, Belle, Lady Hatt, Annie, and Clarabel, 2009-present)
- Alphablocks (Various)
- The Amazing World of Gumball (Nicole Watterson, Penny Fitzgerald, Teri, Jackie Wilson, Margaret Robinson, Penny's Sister, Siciliana Pepperoni, School Nurse, Carmen, Chi-Chi's mother, 2011-present)
- Thunderbirds Are Go (EOS and various other female characters, 2015-present)
- Teletubbies (Voice Trumpets, Tiddlytubbies, 2015-present)
- Miffy's Adventures Big and Small (2015-present)
- While she does put up a great American accent in her role, Gallagher's native accent has slipped twice in "The Gi," "The Mothers," once in "The Job," including various other times, usually when she says the word "anything."
- She voices the titular protagonist of Disney Junior's Henry Hugglemonster (in the UK) with her usual British accent.
- She did however also use an American accent for Disney XD's Dude, That's My Ghost!.
- She voices various female characters, including Emily, Rosie, Mavis, Belle, Lady Hatt, Annie, and Clarabel in the UK and US dubs of Thomas and Friends.
- She, Kerry Shale and Rupert Degas have provided voices for the British television show, Thomas & Friends.