Seems to have been born deaf, in Lapland from a shipwrecked Scottish father and a Lapp mother. After his mother died, his father brought the boy back to Scotland. Taught to read by a professor at the University of Glasgow; claimed to have powers of "second sight" and prediction inherited from his mother, and traveled widely throughout Europe at this "trade"; met the King of England. A book, The History of the Life and Adventures of Mr. Duncan Campbell... appeared in 1720, authored by Daniel Defoe (though this is sometimes disputed), likely with the help of Campbell himself. Defoe also published in 1725 The Dumb Projector; Being a Surprising Account of a Trip to Holland Made by Mr. Campbell... After Campbell's death from pneumonia, another book appeared, Secret Memoirs of the Late Mr. Duncan Campbell, the Famous Deaf and Dumb Gentleman... (1732).
Deaf Lives, p.37-38; Dictionary of National Biography, vol. III, p.808-809; The Quiet Ear, p.83-84.