Someries Castle (sometimes spelt Summeries castle)is a Scheduled Ancient Monument, in the Parish of Hyde, near the town of Luton, Bedfordshire, England. It was built in the 15th century by Sir John Wenlock, whose ghost is reputed to haunt the castle. Although always referred to as a castle it was actually a fortified manor house.

The name of "Someries Castle" was derived from William de Someries (or Somerys), who had a residence on this site, but the title "castle" is contentious since it hardly describes the structure to which it is applied. The site was acquired by Wenlock in 1430 and building the mansion commenced. The house is regarded as one of the first brick buildings in England. The house was never completed by Wenlock, and was partly demolished in the 18th century. The brickwork can still be seen in the remains of the gatehouse, incorporating the chapel and lodge, which still stands today.

                                                         Ruins of Someries Castle, Bedfordshire

The remains of the original manor house and/or the earlier Norman Castle are now visible only as earthworks that outline the plot where the house originally stood, although remains of the gatehouse to the actual manor house and the chapel that was connected to it, are still partially standing. Some bricks from the manor house were used to build the nearby farm houses in the 17th century.

The castle closed to the public in February 2007 in order to make the structure safe and was surrounded by scaffolding, which damaged the original brickwork. It reopened in 2008.