Elizabeth Castle is a historic castle located on a tidal island in St. Aubin's Bay, Jersey, a British Crown Dependency in the English Channel. The castle was named after Queen Elizabeth I of England and was built in the 16th century to protect Jersey from French invasion. Over the years, the castle has undergone numerous modifications and additions, with the most significant renovation taking place during the reign of Charles II in the mid-17th century.

The castle is surrounded by a dry moat that fills with seawater at high tide, making it an island. Visitors can access the castle by foot during low tide, or by taking a ferry service during high tide. The castle's grounds include a military museum, a number of towers and ramparts, and a parade ground. One of the most notable features of the castle is the Martello Tower, which was added in the early 19th century to protect Jersey from Napoleon's forces.