Thompson's film appearances include Four Weddings and a Funeral (1994), Persuasion (1995), Emma (1996), Dancing at Lughnasa (1998), Gosford Park (2001) and Harry Potter and the Deathly Hallows – Part 1 (2010).

[1][2] She made her television debut at the age of 15, starring in the BBC adaptation of the Alison Uttley classic A Traveller in Time, opposite Simon Gipps-Kent, before going on to study at the Bristol Old Vic Theatre School.

[3] In 1979, Thompson made her professional theatre debut at the age of 17 in the play The Schoolmistress by Arthur Wing Pinero at the Royal Exchange in Manchester.

[4] Big-screen roles include Four Weddings and a Funeral,[3] Eat Pray Love, Emma, [3]Dancing at Lughnasa, Gosford Park, Fat Slags,[3] Relative Values and Morris: A Life with Bells On.

[5] She played Miss Bartlett in Andrew Davies' 2007 adaptation of E.M. Forster's A Room with a View[5] and also appeared in the last episode of series 4 of Doc Martin.

[8] Directed by Sir Derek Jacobi, it starred her future brother-in-law Kenneth Branagh as Hamlet, Richard Easton as Claudius and Dearbhla Molloy as Gertrude.

[8] In 1996, Thompson appeared as Amy in Sam Mendes' acclaimed Donmar Warehouse revival of Company, receiving an Olivier Award nomination for her performance.

She also ran the 2010 Marathon for CINI, a charity supporting vulnerable families in India, and 24th Tottenham, a London-based group for children and young adults with special needs.