Emma Thompson's first major film role was in a romantic comedy, The Tall Guy (1989). Her career took a more serious turn with a series of critically acclaimed performances and films, beginning with 1992's Howards End (for which she received an Oscar for Best Actress), the part of Gareth Peirce, the lawyer who got the Guildford Four out of jail, in 1993's In the Name of the Father, The Remains of the Day opposite Anthony Hopkins, and as real life British painter Dora Carrington in the movie Carrington (1995). She won her next Oscar in 1996, for Best Adapted Screenplay for her screenplay adaptation of Jane Austen's Sense and Sensibility, a film in which she also played the lead role. Consequently, Thompson is the first, and so far only, person to have won Oscars for both acting and writing; she has said that she keeps both of her award statues in her downstairs bathroom, citing embarrassment at placing them in a more prominent place.

Thompson's recent television career has included a starring role in the 2001 HBO drama Wit, in which she played a dying cancer victim. In 1984 she starred alongside Stephen Fry and Hugh Laurie as guest stars on British sitcom The Young Ones, in a role that parodies upper class England. In 2003, she joined the cast of Angels in America, playing multiple roles, including one of the titular angels. Her one Emmy Award came as result of her appearance as a guest star in a 1997 episode of the show Ellen; in the episode, she played a parody of herself. She also appeared in an episode of Cheers in 1992. Her character, Nanette "Nanny" Gee, was the host of a children's television program and Frasier Crane's first wife.

Most recently, Thompson appeared in supporting roles in films of a lighter nature, including her role as Sibyll Trelawney in Harry Potter and the Prisoner of Azkaban (2004) and the comedy Love Actually (2003).

The film Nanny McPhee, written by Thompson, was first released in October 2005. Thompson has worked on the project for 9 years, having written the screenplay and starred, alongside her mother (who has a cameo appearance).

Thompson married Kenneth Branagh, with whom she appeared in Fortunes of War, on August 20, 1989. They appeared together several times, in hit films such as Dead Again, Henry V and Much Ado About Nothing, but were eventually divorced in October of 1995.