John Francis Campbell (Iain Frangan Caimbeul, known in Scottish Gaelic as Iain Òg Ìle ('Young John of Islay'); born in Islay, 29 December 1821 — died in Cannes, 17 February 1885), Celtic scholar, educated at Eton and Edinburgh, was afterwards Secretary to the Lighthouse Commission. He was an authority on Celtic folklore, and published the bilingual Popular Tales of the West Highlands (4 vols., 1860—62), and Gaelic various texts.
Campbell also invented the sunshine recorder that bears his name as the Campbell—Stokes recorder.