The ruins of Sherborne Old Castle are located within the grounds of New Sherborne Castle. It was built as a fortified palace by Roger de Caen, Bishop of Salisbury in the 12th century. He was also King Henry I's Chancellor and most senior advisor.

It's most famous resident was Sir Walter Raleigh. After two sieges during the English Civil War, the castle was badly damaged. Today, only the Southwest Gatehouse, the Great Tower and parts of the North Range survive.