Sally Castle was born in Reading. She graduated from Maidstone College of Art and worked as a designer in London for ten years. Since then she has worked as an independent designer and illustrator and has designed covers and/or illustrated many books for Two Rivers Press. In 2022 Sally’s illustrated book The Happy Prince was long-listed for the World Illustration Awards; she also had her first solo exhibition at The Caversham Framer, followed by another in 2025. In 2026 Sally was invited to be the president of Reading Guild of Art and was selected to be an Associate member of the SFGA The Drawing Society. Public work includes the Walking Words panels at Chatham Place and the Forbury Square stone both in Reading.

Some of her work is in the permanent collection in Reading Museum. Her work has been selected for the SFGA exhibition at the Mall Galleries, the Royal West of England Open Exhibition and Ironbridge Print Competition