Clitheroe Castle is a ruined early medieval castle in Clitheroe in Lancashire, England. It was the caput of the Honour of Clitheroe, a vast estate stretching along the western side of the Pennines.Its earliest history is debated but it is thought to be of Norman origin, probably built in the twelfth century. Property of the de Lacy family, the honour later merged with the earldom and then Duchy of Lancaster. Given to George Monck, 1st Duke of Albemarle in 1660, the castle site remained in private ownership until 1920, when it was sold to the people of Clitheroe to create a war memorial. Today the buildings on the site are the home of Clitheroe Castle Museum.
The keep is the second smallest surviving stone-built keep in England. The castle was listed as a Scheduled Monument on 10 April 1915. It was Grade I listed on 19 May 1950.