Jessica Stewart Dismorr was born at Gravesend in Kent, and moved with her family to Hampstead in the 1890s.
She attended the Slade School of Art, 1902-03, before training under Max Bohm at Etaples, and at the Académie de La Palette in Paris, 1910-13, where she studied under Jean Metzinger and was in the circle around the Scottish Colourist, John Duncan Fergusson.