Laemostenus is a genus of ground beetles present on all continents on Earth, except Antarctica. There are nearly 200 species in the genus, divided into several subgenera. Beetles of the genus are about 8 to 28 millimeters long. Many are dark in color with a blue or purple sheen. Others, especially subterranean and cave-dwelling species, are depigmented, much lighter in color, with reduced eyes.