Manorbier Castle is an 11th century Norman castle located five miles south-west of Tenby in Pembrokeshire, South Wales, in the village of Manorbier.

The castle was originally built as a wooden hall with earthwork defences on land granted to Odo de Barri, a Norman knight, at the end of the 11th century. William de Barri, Odo's son, began work on a stone structure in the first half of the 12th century. Portions of this 12th century building remain today. Gerald of Wales, known as Geraldus Cambrensis, the great twelfth century scholar and son of William de Barri, was born in the castle in 1146. On his father's side, Gerald of Wales was the grandson of the legendary Welsh princess Nest verch Rhys.

Showing an understandable bias toward his birthplace, Gerald of Wales wrote of Manorbier: "In all the broad lands of Wales, Manorbier is the most pleasant place by far."

Because the defensive properties of the castle were never really put to the test, it remains remarkably well-preserved. In 1880, the castle was partially restored by J.R.Cobb, a tenant who, as well as carrying out repairs to the decaying buildings and walls, built himself a new house at the end of the Tudor barn. The house is currently available as a holiday let.

The castle is currently open to the public. Visitors may see a chapel, crypt, dungeon and well (with rumoured secret smugglers' passage). The castle is also known for its beautiful gardens. Nearby are the castle's dovecote and mill.

The castle served as the backdrop for Cair Paravel in the BBC version of The Chronicles of Narnia. The 2003 motion picture I Capture the Castle was also filmed at the castle, which was used for both internal and external scenes.