Anthrax is a genus of bombyliid flies, commonly known as "bee-flies" due to their resemblance to bees.
Most are dull black flies, and are usually small to medium in size, 4–20 millimetres (0.2–0.8 in), and many species have striking wing patterns.
While worldwide in distribution, most species are from the Palaearctic and Afrotropic regions.
The genus includes species parasitic on tiger beetles – an unusual trait among the bee-flies.
Many North American species parasitize solitary wasps.