Arroyo Seco Municipality is a municipality in the Mexican state of Querétaro in central Mexico.

Querétaro is a state in North Central Mexico, divided into 18 municipalities. According to the 2020 Mexican census, it is the twenty-first most populated state out of thirty-two with 2,368,467 inhabitants and the sixth smallest by land area spanning 11,690.6 square kilometres (4,513.8 sq mi). The largest municipality by population is Querétaro, with 1,049,777 residents, while the smallest is San Joaquín with 8,359 residents. The largest municipality by land area is Cadereyta de Montes, with an area of 1,347.40 km2 (520.23 sq mi), and the smallest is Corregidora with 234.90 km2 (90.70 sq mi). The newest municipalities are Ezequiel Montes, Pedro Escobedo and San Joaquín, established in 1941.