Medininkai Castle is a medieval castle built in Lithuania in the late 13th century or the first quarter of the 14th century. The defensive parameter of castle was 6.5 hectares and it is the biggest enclosure type castle in Lithuania.

The castle was built on plain ground and was arranged for flank defense. Rectangular castle's yard coverred around 1.8 hectares and was protected by 15 meter height walls, which were 2 meters in width. The castle had 4 gates and towers. The main tower (donjon), about 30 meters in height, was used and for residential quarters. Medininkai was first mentioned in 1392. Castle was badly damaged by a major fire in the late 15th century. Because of increased use of fire arms, this type of castle was no longer suited for defensive purposes and was later used as a residence. During the 17th – 18th centuries it was reorganized into a farm and a bakery.