Joshua Mathias O'Connor (born May 20, 1990) is a British actor. After training at the Bristol Old Vic Theatre School, he had supporting roles in television series such as Doctor Who in 2013 and Peaky Blinders in 2014. He had his breakthrough playing the lead role of a sheep farmer in Francis Lee's romantic drama God's Own Country (2017), for which he won a British Independent Film Award.

For portraying a young Charles III in the Netflix drama series The Crown (2019–2020), O'Connor won a Primetime Emmy Award and a Golden Globe Award. He has since starred in the period dramas Emma (2020) and La Chimera (2023) as well as Luca Guadagnino's Challengers (2024) and Rian Johnson's Wake Up Dead Man (2025).