Lieutenant-Colonel Sir Ian Douglas Campbell-Gray (14 July 1901 – 21 March 1946) was a British soldier serving in the Royal Engineers. His parents were Henry Tufnell Campbell and Ethel Evely Gray Campbell, Baroness Gray. He married Lady Diana Cavendish on 7 July 1942. He competed in the individual and team épée fencing events at the 1936 Summer Olympics.