Folsom State Prison is a California State Prison located in the city of Folsom, 20 miles (32 km) North East from the state capital of Sacramento. Opened in 1880, Folsom is the second-oldest prison in the state of California after San Quentin. Folsom was one of the first maximum security prisons, and as such witnessed the execution of 92 condemned prisoners over a 42-year period. It is possibly best-known in popular culture for two concerts performed at the facility by musician Johnny Cash in the late 1960s. Folsom State Prison is one of 33 prisons operated by the California Department of Corrections and Rehabilitation.

Currently, like the entire California prison system, it suffers from massive overcrowding.