Lieutenant-General Sir William Boog Leishman, was a Scottish pathologist and British Army medical officer. He was Director-General of Army Medical Services from 1923 to 1926.

Romanowsky staining is a prototypical staining technique that was the forerunner of several distinct but similar stains widely used in hematology and cytopathology. Romanowsky-type stains are used to differentiate cells for microscopic examination in pathological specimens, especially blood and bone marrow films, and to detect parasites such as malaria within the blood.