Leishman stain is a vital staining solution used in laboratory settings for the microscopic examination of blood and bone marrow samples. It is named after the British physician William Boog Leishman, who developed the staining technique in the early 20th century.

Leishman stain is primarily used for the identification and characterization of blood cells, particularly white blood cells (leukocytes) and blood parasites. It is commonly employed in hematology and pathology laboratories for diagnostic purposes, research, and teaching.