McAdam or MacAdam is a Scottish Gaelic clan which originated as a branch of Clan Gregor. As a surname it is most prominent in the Galloway and Ayrshire regions of Scotland. Some of their descendants are also to be found in Ireland, the United States, Australia and Canada. Notable people with the surname include:
Adrian McAdam (born 1971), Australian Rules footballerColin McAdam (novelist), a Canadian novelistDavid MacAdam (1910-1998), an American color scientistDoug McAdam (born 1951), an American sociologist studying social movementsElliot McAdam (born 1951), an Australian politician and Northern Territory Cabinet memberGilbert McAdam (born 1967), Australian Rules footballerGreg McAdam (born 1961), Australian Rules footballerJohn Loudon McAdam (1756-1836), a Scottish engineer noted for inventing the process of "macadamization" of roads.John McAdam (businessman), an American businessmanJohn McAdam (politician) (1807-1893), Irish-born politician in New Brunswick, CanadaJohn Macadam (1827-1865), an Australian (Scottish-born) chemist, medical teacher and politician, after whom the Macadamia nut is namedKeith McAdam, Scottish cricketer and specialist in tropical diseasesMacadam, a British illustrator active during the 1920s and 1930sPatrick "Pat" MacAdam is a Canadian writerSean McAdam, an American baseball writer