Especially common as an African-American and Black-British name. The reasons for its popularity are not clear. It may well be a transferred use of the English surname Corey, which is derived from the Old Norse personal name Kori.
Irish and English: 1. nickname for a brave or powerfully built man, from Middle English stout ‘steadfast’. 2. from the Old Norse byname Stútr ‘gnat’, denoting a small and insignificant person. 3. possibly also a habitational name from a minor place named with the Old English element stūt ‘stumpy hillock’, which is found as a component in various Devon place names.