Tilston was nine years old when he auditioned for and was cast in his first professional role of youngChristopher Robin Milne in Simon Curtis' biographical film Goodbye Christopher RobinstarringDomhnall Gleeson and Margot Robbie, and ten years old by the film's release in 2017. Tilston made his television debut when he began starring as Gregory, the seventh Bridgerton child and youngest son in the family, in the 2020 Netflix period drama Bridgerton, a Shondaland-produced adaptation of the Regency romance novels by Julia Quinn.