Santo Domingo Ingenio is a town and municipality in Oaxaca in south-western Mexico.

[1] The municipality covers an area of 354.68 km² at an average elevation of 40 meters above sea level.

The town lies on the Pan-American highway, connecting it to Santiago Niltepec and Juchitán de Zaragoza.

Wild fauna include armadillo, rabbit, coyote, opossum and birds common to the region.

The main economic activity is agriculture, with crops such as maize, sorghum, peanuts, watermelon, melon, sweet potato, cucumber, pumpkin, sesame and sugar cane.