Largest prison (population)
Silivri Penitentiaries Campus
Türkiye (Istanbul)

The largest prison in the world is the Silivri Penitentiaries Campus (Silivri Ceza İnfaz Kurumları Kampüsü, better known simply as Silivri Prison), located in the north-western suburbs of Istanbul, Turkey. The prison complex was designed to house around 11,000 inmates when it was opened in 2008, but a Turkish parliamentary investigation in November 2019 found that the population had risen to 22,781.

Other extremely large prisons include Riker's Island Jail in New York, USA, which had a pre-COVID average population of about 10,000 inmates on any given day (down from around 14,000 at its peak) and the Tihar Jail Complex in Delhi, India, which has a population of 12,106 inmates as of Dec 2019. The Delhi prison system as a whole (including the Rohini and Mandoli prison complexes) has a population of 17,534 and a official capacity of 10,026.

Another facility that is often mentioned in discussions of record-breaking prison populations is LA County Jail, which had an average daily population of almost 20,000 before the COVID-19 pandemic. The LA Country Jail figures are for the entire prison system administered by the LA County Sheriff's Department, which comprises seven facilities spread across the city and its outskirts.