The longest prison riot in British penal history began at Strangeways Prison in Manchester, lasting 25 days.

The 1990 Strangeways Prison riot was a 25-day prison riot and rooftop protest at Strangeways Prison in Manchester, England. The riot began on 1 April 1990 when prisoners took control of the prison chapel, and quickly spread throughout most of the prison. The incident ended on 25 April when the final five prisoners were removed from the rooftop. One prisoner was killed during the riot, and 147 prison officers and 47 prisoners were injured. Much of the prison was damaged or destroyed, with the cost of repairs coming to £55 million. It was the longest prison riot in British penal history.

HM Prison Manchester is a Category A and B men's prison in Manchester, England, operated by His Majesty's Prison Service. It is still commonly referred to as Strangeways, which was its former official name derived from the area in which it is located, until it was rebuilt following a major riot in 1990.