Bastøy Prison (Norwegian: Bastøy landsfengsel) is a minimum-security prison on Bastøy Island, Norway, about 75 kilometers (46 mi) south of Oslo. The prison is on a 2.6 square kilometer (1 square mile) island and hosts 115 inmates. The prison is about one hour commuting distance from Oslo.
Once a prison colony for young boys, the facility now is trying to become the first ecological prison in the world. Reoffending rates have been reported at 16%, compared to a European average of around 70%. Inmates are housed in wooden cottages and work the prison farm. During their free time, inmates have access to horseback riding, fishing, tennis, and cross-country skiing. The only access to the prison is from a ferry that departs from Horten.