Azkaban
| Location | Island in the North Sea |
| Owners | Ekrizdis (Formerly), British Ministry of Magic |
| Employees | Dementors (Formerly), Aurors |
Originally created by the wizard Ekrizdis as a place to torture Muggles, Azkaban is an island fortress used by the British Ministry of Magic as a prison. After Ekrizdis died, the enchantments fell and the Ministry became aware of it. Although infested with Dementors, the island became a prison for convicted criminals with the Dementors as guards.
Notable prisoners include Sirius Black, Bellatrix Lestrange, Bartemius Crouch Jnr, Lucius Malfoy, Dolores Umbridge, and Delphini, among many others. During the First Wizarding War, many suspects were imprisoned without trial, including Sirius Black, who was innocent. Sirius became the first person to escape the prison, using his illegal animagus form to do so.
Many of the prisoners were serving life sentences for their involvement in the Wizarding Wars. The Dementors meant that many of them died of despair. There was a graveyard on the island for prisoners to be buried.
During the Second Wizarding War, the Dementors defected to Voldemort's side, and allowed many notorious Death Eaters to escape. After the conclusion of the War, the Dementors were expelled from the island as they were deemed inhumane and untrustworthy. As of 1998, the prison is guarded by Aurors on rotation.