Yamatocetus canaliculatus is an extinct species of eomysticetid baleen whale from the Late Oligocene of Japan.

The holotype specimen, a partial skeleton, was discovered by curator Toshiyuki Kamei in October 1981 in the Ashiya Group of the Jinnobaru Formation on the island of Kyushu, and stored in the Kitakyushu Museum of Natural History and Human History.

The auditory bulla in the ear is more similar to primitive baleen whales and archaeocetes.

The shoulder blade was concave on the side facing the ribs, a primitive feature for baleen whales.

[1] Yamatocetus was an early filter feeder, and its teeth, if it had any, were likely vestigial and served no purpose.