Pénjamo is the seat of Pénjamo municipality, one of 46 municipalities of Guanajuato, Mexico. It was cofounded in 1549 by Guamares, Purépechas, and Otomis prior to the outbreak of the Chichimeca war.

Guanajuato, officially the Free and Sovereign State of Guanajuato, is one of the 32 states that make up the Federal Entities of Mexico. It is divided into 46 municipalities and its capital city is Guanajuato.