Sir Robert Brackenbury (died 22 August 1485) was an English courtier, who was Constable of the Tower of London during the reign of Richard III.
Barnard Castle had passed to the Duke of Gloucester (later Richard III) in the right of his wife, Anne Neville in about 1474.
Shortly after Richard took the throne Brackenbury received a number of appointments, including Constable of the Tower of London.
After the collapse of the Buckingham Revolt he was rewarded with large grants of land in the south-east of England forfeited by Rivers and the Cheney family and in 1484 was appointed sheriff of Kent.
In 1485, when news arrived that Henry Tudor had landed in Wales he was ordered to escort Lords Hungerford and Bourchier to Leicester but en route they escaped.
In a document antedating Henry Tudor's rule, Brackenbury was charged with having "assembled to them at Leicester ... a great host, traitorously intending, imagining and conspiring the destruction of the king's royal person, our sovereign liege lord".
Brackenbury's attainder was partly reversed in 1489 in favour of his sisters and bastard son, allowing them to recover the family lands but not the new grants from Richard III.