Kelly Macdonald (born 23 February 1976) is a Scottish actress. Known for her performances on film and television, she has received various accolades including a BAFTA Award, a Primetime Emmy Award, and four Screen Actors Guild Awards.

Macdonald made her film debut in Danny Boyle's Trainspotting (1996). She was nominated for the BAFTA Award for Best Actress in a Supporting Role for her role in the Coen brothers film No Country for Old Men (2007). During her career she has taken roles in Elizabeth (1998), Gosford Park (2001), Intermission (2003), Nanny McPhee (2005), Harry Potter and the Deathly Hallows – Part 2 (2011), Anna Karenina (2012), T2 Trainspotting (2017), and Operation Mincemeat (2021). She voiced Princess Merida in the Disney Pixar animated film Brave (2012).