Isabelle de Steiger, née Lace (28 February 1836 – 1 January 1927), was an English painter, theosophist, occultist and writer. She became a member of several esoteric societies in London, and was a close friend and co-worker of Anna Kingsford.
Isabelle Lace was born in Liverpool, the daughter (and one of seven children) of Joshua Lace, a solicitor. She was educated first in Liverpool, then in Stratford-upon-Avon. In 1861, she married a Swiss cotton merchant, Rudolf Adolf von Steiger von Riggesberg. The couple divided their time between England and Switzerland, then settled down, for professional reasons, in Egypt, where her husband died of Tuberculosis in 1870.
Isabelle de Steiger returned to England in 1874 and studied art, first at the Heatherley School of Fine Art, then at the Slade School of Fine Art in London. Having obtained her degree, she began a career as a professional painter, going on to exhibit at various galleries, such as the Royal Academy in London, and the Walker Art Gallery in Liverpool. Her style was strongly influenced by Lawrence Alma-Tadema and his historical paintings, such as Cleopatra after the Battle of Actium etc. She was also known for her flower painting and book illustrations. She illustrated, for example, the occult magazine The Unknown World (1894-1895), edited by A. E. Waite. She painted some figures in the Theosphical movement but unfortunately much of her work was destroyed in a fire. She also experienced the prevailing prejudice against women which made it difficult to rent studio space and attend life classes, as well as social obstacles to women having an independent career.