Eodelphinus is an extinct genus of oceanic dolphins belonging to the family Delphinidae.

Eodelphinus differs from all other delphinids by having a medially positioned premaxillary foramen, a partially transversely directed suture line between the palatine and pterygoid on the palate, and prominently long and ventrolaterally extended posterior process of the periotic with the attenuating posterior bullar facet.

[1] Eodelphinus was originally described in 1977 as a new species of Stenella, S. kabatensis, from a partial skull found in marine deposits in Hokkaido, Japan.

[2] Later, Ichisima (2005) questioned the attribution of S. kabatensis to Stenella, stressing the need for re-assessment of the taxon.

[3] Subsequent study by Mizuki Murakami and colleagues published in 2014 showed that S. kabatensis is the most basal member of Delphinidae, necessitating erection of the new genus Eodelphis.