Living in the slum of Katwe in Kampala, Uganda, is a constant struggle for 10-year-old Phiona (Madina Nalwanga) and her family. Her world changes one day when she meets Robert Katende (David Oyelowo) at a missionary program. Katende coaches soccer and teaches children to play chess. Curious, Phiona approaches and learns the game. She becomes fascinated with it and soon becomes a top player under Katende's guidance. Over several years, her success in competitions and tournaments leads to greater competitions, stress, and identity issues. Phiona must learn more than the game as she is exposed to life outside Katwe. Her education, both formally and informally, continues as she dreams of escaping a life of poverty for herself, her mother, and her siblings.