| Named By: | R. Kellogg in 1968 |
| Time Period: | Miocene |
| Location: | Japan - Korematsu Formation and Nagura Formation. USA, Mayland - Calvert Formation, Calvert Beach Member, and Virginia - Calvert Formation, Plum Point Member |
| Size: | Total length about 6 meters long |
| Diet: | Filter feeder |
| Fossil(s): | Several individuals represented by skulls and partial post cranial remains |
| Classification: | | Chordata | Mammalia | Cetacea | Mysticeti | |
Diorocetus is an extinct genus of baleen whale, belonging to the family Pelocetidae. Fossils are found in Miocene-aged marine strata in North America and Japan.