Castello Sforzesco, or Sforza Castle, is a Renaissance fortress in Milan, Italy. It was built in the 15th century by Francesco Sforza, the Duke of Milan, and was later renovated and expanded by various rulers over the centuries. The castle has a distinctive brick facade and is surrounded by a moat and massive defensive walls.

Today, the Castello Sforzesco is a museum complex that contains numerous art collections, including paintings, sculptures, and decorative arts. Some of the highlights include works by Michelangelo, Leonardo da Vinci, and Titian, as well as an impressive collection of musical instruments. The castle also houses several historical and archaeological museums, including a museum dedicated to the history of Milan, a museum of ancient art, and a museum of prehistory and protohistory.

The castle itself is also a notable architectural and historical site. It was the seat of power for the ruling Sforza family, and was the site of many important historical events, including the wedding of Francesco Sforza's son, Ludovico il Moro, and the imprisonment of Leonardo da Vinci. The castle has undergone several restorations over the years, and is now considered one of the most important cultural sites in Milan.