Other notable film roles include the voice of Wendolene Ramsbottom in Wallace and Gromit: A Close Shave (1995) and as Leslie Tiller in Hot Fuzz (2007).

Although she had already appeared in other television programmes including The Benny Hill Show (1957), Hancock's Half Hour (1957) and The Adventures of Robin Hood (1958), Reid's first major acting role was as the character of Valerie Tatlock (later Barlow) on Coronation Street.

[9]On 27 January 1971, 18.26 million viewers watched as Valerie Barlow was written out of the soap, dying after being electrocuted by a hairdryer with a faulty plug.

Following a break from acting to bring up her son, during which time she made occasional TV appearances for Granada, such as in Crown Court, Reid resumed her career on stage and television in the 1980s.

She also had a major role in the ITV drama series Life Begins, which ran from 2004 to 2006, in which she appeared alongside Caroline Quentin and Frank Finlay.

[14] In 2010, she began playing Mrs Thackeray, the cook, in the BBC's short-lived revival series of Upstairs Downstairs, and also appeared in Five Days,[15] New Tricks and Moving On.

In 2011 Reid had a major part in Marchlands,[16] a five-part ITV supernatural drama, made a guest appearance in Doc Martin and played a supporting role in The Jury II.

[17] In 2012 Reid began starring as Celia alongside Sir Derek Jacobi as Alan in the BBC romantic comedy-drama series, Last Tango in Halifax.

[24] In 2017, Reid starred alongside Timothy Spall in "The Commuter", an episode of the Channel 4/Amazon Video anthology series Electric Dreams.

[28] In 2023 she starred alongside Timothy Spall and Éanna Hardwicke in the BBC true-life crime drama The Sixth Commandment, for which she nominated for the 2024 British Academy Television Award for Best Actress.

Her other film appearances include Love and Death on Long Island (1997); The Mother (2003), for which her performance secured her a nomination for the BAFTA Award for Best Actress in a Leading Role in 2004;[33] Hot Fuzz (2007);[34] Cemetery Junction (2010); and Song for Marion (2013).

[38] In June 2007, Reid played the role of Jack's mother in Stephen Sondheim's Into the Woods, at the Royal Opera House in Covent Garden.

[41] From September to November 2012, Reid appeared at London's Old Vic, in a production of Ibsen's Hedda Gabler, starring Sheridan Smith.

From October to December 2017, Reid returned to the West End opposite Eve Best in Oscar Wilde's A Woman of No Importance at the Vaudeville Theatre.

[45] From March to May 2023, Reid appeared in the UK premiere of Marjorie Prime by Jordan Harrison, at the Menier Chocolate Factory in London.