Mogami Tokunai (最上 徳内, c. 1755 – October 14, 1836) was a Japanese samurai, geographer and explorer.

Mogami was born in Dewa Province in what is now part of Yamagata Prefecture).

[1] He explored and mapped Hokkaido and Sakhalin and some of the Kuril Islands in 1785–1786.

In his reports to the Tokugawa shogunate, he emphasized the need to defend the islands.

In a statistical overview derived from writings by and about Mogami Tokunai, OCLC/WorldCat encompasses roughly 20+ works in 40+ publications in 3 languages and 130+ library holdings.