The name of Tilley is said to be of Norman origin, and derived from the village of Tilly in the department of Clavados in Normandy. It was undoubtedly taken into England at the time of the Conquest in 1066. It was found on ancient records in the various forms of Tylly, Tilli, Tillie, Tylye, Tilly, and Tilley, of which the last is the most generally accepted form in the US.
Families of this name were found at early dates in the English counties of Somerset, Dorset, Devon, York, Cornwell, and London. They were, for the most part, of the landed gentry and yeoman of Great Britain. It is said that the English families of the Tilley name trace their descent from a Norman knight, who followed William the Conqueror in the invasion of England, and was rewarded for his services by grants of land in England.