Katherine Kelly is an English actress. She rose to fame for her role as Becky McDonald in the ITV soap opera Coronation Street (2006–2012), for which she received numerous awards, including the British Soap Award for Best Actress (2009) and the NTA for Best Serial Drama Performance (2012).

Kelly's subsequent television roles include Lady Mae in Mr Selfridge (2013–2014, 2016), DS Jodie Shackleton in Happy Valley (2016), Miss Andrea Quill in Class (2016), Jane Lowry in Strike Back (2017–2018), DCI Natalie Hobbs in Crime: UK (2019–2020), Elizabeth Sutherland in Gentleman Jack (2019–2022), DS Karen Renton in Liar (2020), Sally Wright in Innocent (2021) and Angela van den Bogerd in Mr Bates vs the Post Office (2024).

Katherine Kelly was born in Barnsley, South Yorkshire. She grew up in both South Yorkshire and the United States. She has strong ties to The Lamproom Theatre in Barnsley, founded in 1998 by her father John (from Castleisland, County Kerry, Ireland), and she has regularly supported charity events held there.

She trained at the Royal Academy of Dramatic Art alongside fellow students Meredith MacNeill, Leo Bill, Elliot Cowan, Laurence Fox and actor and novelist Anna Hope, graduating in 2001.