Santa María del Oro is a municipality and municipal seat in the Mexican state of Jalisco. It is located in the south of the state and has boundaries with the municipalities of El Nayar, Tepic, Ahuacatlán, Jala, San Pedro Lagunillas, La Yesca, and Xalisco. The population was 21,688 in 2005, with the municipal seat of the same name having 3,314 inhabitants. The total area was 912.90 km².