Altar (O'odham: Wawuk) is small city and municipal seat of Altar Municipality in the Mexican state of Sonora.

It is located in the northwest region of the state at 30°42′49″N 111°50′07″W / 30.71361°N 111.83528°W / 30.71361; -111.83528.

The town of Altar is situated on the important Mexicali to Hermosillo Highway (Federal Highway 2).