Wawyachtonoc were an Algonquian-speaking Indigenous people of the Northeastern Woodlands who lived in east-central New York and northwest Connecticut.

The autonymous ethnonym—or endonym—Wawyachtonoc is often translated into English as "eddy people" or "people of the curved channel".

The name Wawyachtonoc is also transcribed and rendered, in Latin script, as Wyachtonok, Wawayachtonoc, and Wyaghtonok. From this term derives the demonym Weantinock—the name given by the Wawyachtonoc, and toponym used by them in reference to, their primary community and chief settlement, historically located along the confluence of the Housatonic River and its tributary Still River in the vicinity of what is today downtown New Milford, Connecticut.

The traditional territory of the Wawyachtonoc covered much of today's Litchfield County, Connecticut, and extended very slightly into what is now easternmost Columbia and Dutchess counties in New York.

In 1687, the Wyachtonok, originally subgroup of Paugussett, joined the Mohican Confederacy.

The majority of the Wawyachtonoc were converted to Christianity, beginning in 1740, by Moravian missionaries. During this period Wawyachtonoc populations became concentrated at the Moravian missions at Shekomeko and Scaticook. Some of them moved to Moravian Indian communities in Pennsylvania.

In the 1830s, some Wawyachtonoc were displaced to Wisconsin. These Wawyachtonoc descendants are now part of the Stockbridge–Munsee Community and Brothertown Indians of Wisconsin, while those that remained in Connecticut are part of the Schaghticoke Tribal Nation, a state-recognized tribe.