Calvillo is a city located in the Mexican state of Aguascalientes. Situated in the southwestern corner of the state at coordinates 21°51′N 102°43′W, it is positioned approximately 52 kilometers from the state capital, Aguascalientes.
The city serves as the municipal seat for the surrounding municipality of Calvillo. It is recognized as the second most populated city in the state, surpassed in importance only by the capital city.