Tumbiscatío is a municipality located in the southwest region of the Mexican state of Michoacán. It covers a total area of 2,069.48 square kilometres and serves as the least densely populated municipality within the state.
The municipality is bordered by Apatzingán and La Huacana to the north, Arteaga to the east and south, Coalcomán de Vázquez Pallares to the southwest, and Aguililla to the west. The city of Tumbiscatío de Ruiz serves as the municipal seat.
According to the 2005 census, the municipality had a population of 8,373 inhabitants.