[2][3] After graduating from the Bristol Old Vic Theatre School,[4] Richardson began her career in 1979 and made her West End debut in the 1981 play Moving,[4] before being nominated for the 1987 Olivier Award for Best Actress for A Lie of the Mind.

"[15] Richardson enrolled at the Bristol Old Vic Theatre School,[16] where she studied alongside Daniel Day-Lewis and Jenny Seagrove, having started out with juvenile performances in Cinderella and Lord Arthur Savile's Crime at the Southport Dramatic Club.

[19] In 1985, Richardson made her film debut as Ruth Ellis, the last woman to be hanged in the United Kingdom, in the biographical drama Dance with a Stranger.

Around the same time, Richardson played a comedic Queen Elizabeth I, aka Queenie, in the British television comedy Blackadder II.

Following Dance with a Stranger, Richardson turned down numerous parts in which her character was unstable or disreputable, including the Glenn Close role in Fatal Attraction.

Richardson has appeared in supporting roles in film, including Vanessa Bell in The Hours, Lady Van Tassel in Sleepy Hollow and Patsy Carpenter in The Evening Star.

Richardson also appeared as Queen Rosalind of Denmark in The Prince and Me and as the ballet mistress Madame Giry in the film version of the Andrew Lloyd Webber musical The Phantom of the Opera (2004).

In 2005, she appeared in the role of Rita Skeeter, the toxic Daily Prophet journalist in Harry Potter and the Goblet of Fire.

[21] In 2014, Richardson was cast as Queen Ulla in Maleficent, where she was to play the titular character's aunt, but her role was cut from the film during post-production.