John McAdam

John McAdam may refer to:


 * John Loudon McAdam (1756–1836), Scottish engineer noted for inventing the process of "macadamization" of roads
 * John McAdam (politician) (1807–1893), Irish-born politician in New Brunswick, Canada
 * John Macadam (1827–1865), Australian (Scottish-born) chemist, medical teacher and politician, after whom the Macadamia nut is named
 * John McAdam (businessman) (born circa 1970), American businessman