Sophie Fedorovitch (1893-1953) had a formative influence on the designs of English ballet as it developed during the 1930s and 1940s. Trained as a painter, she was a Polish-born Russian who adopted England as her homeland. Reticent by nature, little is documented about Fedorovitch's life and work. This paper examines her sources of influence, comparing her work to that of one of her better known contemporaries, the French artist and designer Christian Berard (1902-1949), to whom she was sometimes compared. The analysis shows that Fedorovitch deserves to be recognised as Berard's equal, an accomplished ballet designer with her own unique style. The impact of other influences on her ballet designs is also explored, including music, choreography and nature. (Contains 4 figures and 1 table.)