Hirudo is a genus of leeches of the family Hirudinidae. It was described by Linnaeus in 1758. There are two well-accepted species within the genus: * Hirudo medicinalis Linnaeus, 1758 * Hirudo nipponia Whitman, 1886 Three other species, previously synonymized with Hirudo medicinalis, were described in 2005 and are gaining acceptance: * Hirudo verbana * Hirudo orientalis * Hirudo sulukii * Hirudo troctina