A former hairdresser, Gallagher's big break came when she starred as Bernie in
The Commitments (1991), followed by a supporting role in the BBC drama
You, Me & Marley (1992). She had small parts in
Pulp Fiction (1994) and
Star Wars: Episode I – The Phantom Menace (1999). Other film appearances include
Mary Reilly (1996),
Divorcing Jack (1998),
Thunderpants (2002),
Skagerrak (2003),
Tristan & Isolde (2006),
Last Chance Harvey (2008),
Sherlock Holmes (2009) and
Grabbers (2012). In 2009, Gallagher starred alongside a well-known cast on the
MySpace/
Vertigo Films production
Faintheart and starred in the
BBC Three comedy TV series
Pramface in 2012. On television, she played the mother of young Nick in the
BBC drama
Nick Nickleby. She played Trisha Meehan in
The Field of Blood and Ada Mason in ''
Agatha Christie's Poirot'' Series 10 episode "The Mystery of the Blue Train". In 2019, she began her role as Carol, the sister of amateur boxer Ashley in the Sky Original series Brassic. An image of Gallagher, in character as Bernie McGloughlin in the film
The Commitments, was
featured on an Irish postage stamp as part of the
Ireland 1996: Irish Cinema Centenary series issued by
An Post. The image includes her
The Commitments co-stars
Angeline Ball as Imelda Quirke,
Maria Doyle Kennedy as Natalie Murphy and
Andrew Strong as Deco Cuffe. ==Pledge==