Reigate Castle is a former castle in the town of Reigate in the county of Surrey, England. None of the castle buildings survive today, but a cave below the site, considered to be part of the castle, still exists. Known as "Baron's Cave", it is occasionally open to the public for tours.
The site of the castle is known as "Castle Grounds", and is a public park. At its entrance stands a folly, built in the 18th century, in the form a medieval castle gateway.