Morawanocetus is a genus of extinct primitive baleen whale from the family Aetiocetidae that existed during the Chattian stage of the Oligocene epoch.

Three new species, dating from 17 to 19 million years ago, were unearthed between 2000 and 2005 in a road-widening project in California.

[4][5] Morawanocetus was divergent, with wide crania, elaborate cheek, tooth crowns, and short necks.

[2] The first fossils of Morawanocetus were found in the Chattian-aged Morawan Formation of Upper Oligocene Hokkaido.

The more recent findings are the first Morawanocetus fossils found in California, a genus more commonly known to Japan.