Okwanuchu is an extinct Shastan language formerly spoken in northern California.

Many words are practically pure Shasta; others are distorted to the very verge of recognizability, or utterly different."

Du Bois,[2] interviewing a survivor of a group that the Wintu called Waymaq ("north people"), who she believed were probably identical to the Okwanuchu, recorded some words, including atsa ("water").

[1] Golla writes that eighteen more words are found, under the name "Wailaki [also meaning 'North People'] on McCloud", in an 1884 work by Jeremiah Curtin; he too recorded atsa ("water"), and five words not found elsewhere in Shastan.

This article related to the Indigenous languages of the Americas is a stub.