Mañihuales River or Mañiguales River (Spanish: Río Mañihuales, Río Mañiguales) is a river in the Isthmus of Ofqui, Aysén Region, Chile. Mañihuales River flows in a SE direction into the Gulf of San Esteban, close to the . At its estuary it joints with San Tadeo River. The river drains much of the swampy Isthmus of Ofqui and originates near Presidente Ríos Lake. Indigenous canoe-faring Chonos used the rivers as part of a north–south route that traversed the Taitao Peninsula and Isthmus of Ofqui. This route was unknown to the colonial Spanish who used San Tadeo River for the same purpose.