Imelda Mary Philomena Bernadette Staunton, (born 9 January 1956) is an English stage and screen actress. After training at the Royal Academy of Dramatic Art, Staunton began her career in repertory theatre in the 1970s before appearing in seasons at various theatres in the UK.

Staunton has since performed in a variety of plays and musicals in London, winning four Olivier Awards; three for Best Actress in a Musical for her roles as the Baker's Wife in Into the Woods (1991), Mrs. Lovett in Sweeney Todd (2013) and Mama Rose in Gypsy (2016), and one for Best Supporting Performance for her work in both A Chorus of Disapproval (1985) and The Corn is Green (1985). Her appearances on stage in The Beggar's Opera (1982), The Wizard of Oz (1987), Uncle Vanya (1988), Guys and Dolls (1996), Entertaining Mr Sloane (2009) and Good People (2014) also earned her Olivier nominations. Staunton has been nominated for a total of 13 Olivier Awards.

Staunton drew critical acclaim for her performance in the title role in the 2004 film Vera Drake, for which she won the BAFTA Award for Best Actress in a Leading Role and the Venice Film Festival Volpi Cup for Best Actress in addition to being nominated for the Academy Award, the Golden Globe and the Screen Actors Guild Award for Best Actress. Her other film roles include Mrs. Blatherwick in Nanny McPhee (2005), Dolores Jane Umbridge in two of the Harry Potter films (2007–2010) and Hefina Headon in Pride (2014), for which she received a nomination for the BAFTA Award for Best Actress in a Supporting Role.

On television, she starred in the sitcoms Up the Garden Path (1990–1993) and Is it Legal? (1995–1998). Her performance in My Family and Other Animals (2005) earned her a nomination for the International Emmy Award for Best Actress, while her roles in Return to Cranford (2009) and The Girl (2012) earned her BAFTA TV Award nominations for Best Supporting Actress. For the latter, she was also nominated for the Primetime Emmy Award for Outstanding Supporting Actress in a Miniseries or a Movie.