Castello di San Giorgio, also known as Mantua Castle, is a historic castle located in the city of Mantua, Italy. It was built in the 14th century and has been extensively modified and renovated over the centuries. The castle is situated on a man-made island, which was created by digging a moat around it and flooding the area. It served as the residence of the Gonzaga family, who ruled Mantua for centuries.

The castle is a massive fortress, with four towers at its corners and a central courtyard. It is surrounded by a wide moat, which was once filled with water. The castle's facade is decorated with intricate carvings and sculptures, including a large statue of the castle's patron saint, St. George, slaying a dragon.

Today, the castle houses the Museo di Palazzo Ducale, which showcases the history and art of Mantua and the Gonzaga family. Visitors can see a range of exhibits, including paintings, sculptures, and furnishings from various periods in the castle's history. The castle also hosts cultural events, such as concerts and exhibitions, throughout the year.