Ernest Cossart (born Emil Gottfried von Holst, 24 September 1876 – 21 January 1951) was an English-American actor.

Cossart was born in Cheltenham, Gloucestershire, the younger of the two children of Adolph von Holst (1846–1901), a professional musician, and his first wife, Clara (née Lediard; 1841–1882).

[4] In the late 1920s, Cossart made a return to the London stage, acting with Alfred Lunt and Lynn Fontanne in a West End transfer of a Broadway success, Caprice.

[5] In 1932, he appeared as Colonel Tallboys in the world premiere of Bernard Shaw's Too True to Be Good, with Beatrice Lillie and Leo G.

[11] During the Second World War, Cossart was a co-founder, with Sir Cedric Hardwicke, Basil Rathbone, and other expatriate actors, of a fund to help artists in distress in Britain.