Omegasyrphus is a genus of hoverflies, with five known species. These are small Microdontinae flies with a distinctive abdominal shape; the second segment is widened, flattened, and flared, with its lateral margin subcircular, thickened, and rounded, and the rest of abdomen (third–fifth segments) narrowed and cylindrical. The larvae feed as scavengers in the nest of the ants. They are native to southern North America.