Roger de Busli (c. 1038 – c. 1099) was a Norman baron who accompanied William the Conqueror (Duke of Normandy) on his successful conquest of England in 1066.
Roger de Busli was born in or around 1038. His surname comes from the town now known as Bully (near Neufchâtel-en-Bray, mentioned as Buslei ar. 1060, Busli 12th century.) in Normandy, and he was likely born there. After the Conquest, Busli was given lands in Nottinghamshire, Derbyshire and the Strafforth wapentake of Yorkshire. These had previously belonged to a variety of Anglo-Saxons, including Edwin, Earl of Mercia. and Rynold de Wynterwade, patriarch of the Wentworth family.
By the time of the Domesday survey de Busli was tenant-in-chief of 86 manors in Nottinghamshire, 46 in Yorkshire, and others in Derbyshire, Lincolnshire and Leicestershire, plus one in Devon. They became the Honour of Blyth (later renamed the Honour of Tickhill), and within it, de Busli erected numerous castles, at Tickhill, Kimberworth, Laughton-en-le-Morthen and Mexborough.
Much of the de Busli's family's leverage came from their familial relationships with the crown through the Counts of Eu. Roger de Busli's wife Muriel was in favour with the queen, to whom she was probably a lady-in-waiting or a kinswoman, evident in the queen's grant to de Busli of the manor of Sandford upon his marriage. The de Buslis had one son, also called Roger, who died as an infant, thus leaving no heirs. Beatrix, probably Roger's daughter (or possibly his sister), married William, Count of Eu.