Sheffield Castle was a castle in Sheffield, England, constructed at the confluence of the River Sheaf and the River Don on the site of a former Saxon long house, and dominating the early town.

The first Sheffield Castle was a wooden motte and bailey type, built for William de Lovetot in the early twelfth century. This was destroyed during the Barons' War in 1266, along with the rest of the town, and was replaced by a larger stone castle in 1270.

By the sixteenth century, the Earl of Shrewsbury had built the alternative residence of Sheffield Manor. The castle was badly damaged in the English Civil War and largely demolished in 1648. The last remains of the castle are preserved under the city's Castle Market and are occasionally open for viewing.