She is also known for her appearances in films, including The Dressmaker (1988), The Witches (1990), Second Best (1993), Life is Sweet (1990), Chicken Run (2000), Corpse Bride (2005), Sunshine on Leith (2013), Absolutely Fabulous: The Movie (2016), as well as the television series Fifi and the Flowertots (2005–2010), Little Princess (2006–2020), and the Sky One sitcom Trollied, as Julie Cook (2011–2015).
While working on Road, a play directed by Jim Cartwright, Horrocks warmed up by doing singing impressions of Judy Garland, Shirley Bassey and Ethel Merman.
[citation needed] Her last West End appearance was in Sweet Panic, the 2003 Stephen Poliakoff drama in which she portrayed a neurotic mother locked in a battle of wills with her disturbed son's psychologist.
[citation needed] She starred in Richard Jones's critically acclaimed production of The Good Soul of Szechuan at the Young Vic in 2008.
[8] In 2024, Horrocks joined the cast of the British premiere production of play Nachtland at the Young Vic theatre, directed by Patrick Marber.
[citation needed] For 10 years, Horrocks appeared with Prunella Scales in commercials for the UK supermarket chain Tesco.
[12] Other television credits include Absolutely Fabulous, Victoria Wood - We'd Quite Like to Apologise, Bad Girl, Boon, Heartland, Hunting Venus, La Nonna, Leaving Home, Never Mind the Horrocks, Nightlife, Wyrd Sisters, Foxbusters, Jericho, Red Dwarf, Some Kind of Life, Suffer the Little Children, The Storyteller, The Garden, Fifi & the Flowertots, Little Princess (the voice of the princess) and Welcome to the Times.
The other contestants were TV and radio presenter Kirsty Young, choreographer Jason Gardiner, and Olympic athlete Greg Rutherford.
On 9 May 2015, she gave a reading at VE Day 70: A Party to Remember in Horse Guards Parade, London that was broadcast live on BBC1.
[14] Horrocks' voiceovers have been used on the films Chicken Run, Christmas Carol: The Movie, Corpse Bride, Garfield: A Tail of Two Kitties, and Tinker Bell.