Mia Honey Winslet Threapleton (born 12 October 2000) is an English actress. The daughter of actress Kate Winslet and painter-filmmaker Jim Threapleton, she made her film debut at the age of 13 with a non-speaking cameo in the period drama A Little Chaos (2014). On television, she co-starred with her mother in the episode "I Am Ruth" (2022) of the anthology series I Am..., and starred in the period drama series Dangerous Liaisons (2022) and The Buccaneers (2023). She had her first lead role in a feature film in the black comedy The Phoenician Scheme (2025).