Michelle Fairley (born 11 July 1963) is an actress from Northern Ireland. She is best known for playing Catelyn Stark in the HBO series Game of Thrones (2011–2013). She has since appeared in the USA Network series Suits (2013), the Fox series 24: Live Another Day (2014), the RTÉ miniseries Rebellion (2016), the science fiction series The Feed (2019), and the Sky Atlantic crime drama Gangs of London (2020–).

Fairley was born in Coleraine to parents Brian and Teresa Fairley, the second eldest of six children. Her father was a popular publican, owner of Fairley's Bar and several off-licences, in Northern Ireland during The Troubles, but Fairley remembers both Catholics and Protestants frequenting the pub.

Fairley appeared in a number of British television shows, including The Bill, Holby City and Casualty. Some of her earlier roles were as Cathy Michaels on ITV1's Inspector Morse in the episode titled "The Way Through The Woods" and as Nancy Phelan in Lovejoy in the episode 9 of Season 3 titled "Smoke Your Nose".

She took over the role of Mrs. Granger from Heather Bleasdale (who had played Mrs. Granger in Chamber of Secrets) in the Harry Potter and the Deathly Hallows films. From 2011 to 2013, Fairley starred as Catelyn Stark (née Tully) in the first three seasons of the HBO fantasy series Game of Thrones, replacing Jennifer Ehle who played the character in the original, unaired, pilot episode.

Fairley joined the cast of the USA Network series Suits for its third season, playing the recurring role of Dr. Ava Hessington, a chemical engineer and oil CEO accused of bribery, and after that, accused for murder. She played Margot Al-Harazi in 24: Live Another Day on Fox. Her film roles included The Invisible Woman (2013) and In the Heart of the Sea (2015). In 2014, Fairley was cast as Margaret Langston in the ABC TV Series Resurrection (2014-2015).

In 2017, it was announced Fairley would appear in a revival of Jim Cartwright's play Road at the Royal Court Theatre In 2018, she played Cassius in Julius Caesar at the Bridge Theatre, alongside David Calder, David Morrissey and Ben Whishaw. In 2019, Fairley led the Virgin Media and Amazon Prime science fiction series The Feed as Meredith Hatfield. As of June 2020, Fairley stars as Marian Wallace in the Sky Atlantic crime drama Gangs of London. She starred as Millie in the 2021 film Nobody Has To Know alongside Bouli Lanners. In 2023, Fairley starred as Princess Augusta in Queen Charlotte: A Bridgerton Story on Netflix. She also contributed to The Gone a TVNZ and RTE coproduction.