The surname Moore is predominantly found in the British Isles. Moore has a number of different origins. Moore can be of locative origin meaning somebody that lived by a moor or a marshy bog. Moore may also derive from the old French term meaning somebody of dark complexion. Moore may also come from the Gaelic term "Mor" meaning great, chief, mighty or proud. There are approximately 700,000 bearers of the surname Moore in the US today..