| Ommatius parvus Bigot, 1875 |
| Ommatius perangustimus Scarbrough, 1990 |
| Ommatius pilosulus (Bigot, 1875) |
| Ommatius pretiosus Banks, 1911 |
| Ommatius pumilus Macquart, 1847 |
| Ommatius willistoni Curran, 1928 |
| Orrhodops Hull, 1958 |
| Orrhodops americanus (Curran, 1930) |
| Orrhodops occidentalis (Williston, 1901) |
| Orthoneuromyia Williston, 1893 |
| Ospriocerus Loew, 1866 |
| Ospriocerus abdominalis (Say, 1824) |
| Ospriocerus aeacides Loew, 1866 |
| Ospriocerus aeacidinus (Williston, 1886) |
| Ospriocerus aeacus (Wiedemann, 1828) |
| Ospriocerus alamoensis Martin, 1968 |
| Ospriocerus arizonensis (Bromley, 1937) |
| Ospriocerus brevis Martin, 1968 |
| Ospriocerus consanguineus (Loew, 1866) |
| Ospriocerus diversus Williston, 1901 |