The Tōkai–Tōsan dialect (東海東山方言 Tōkai–Tōsan hōgen) is a group of the transitional Japanese dialects spoken in the southern and eastern Chūbu region.

These are transitional between Western and Eastern Japanese; which branch of the family they fall in depends on which isoglosses are taken as definitive.

The Echigo dialect is spoken in mainly Niigata Prefecture, formerly known as Echigo Province except north of the Agano River.

They share many grammar features with Western Japanese.

Mountain village dialects that retain fragments of Eastern Old Japanese.