John Sinclair may refer to:
- John Sinclair (bishop) (died 1566), Ordinary Lord and later Lord President in the Court of Session
- Sir John Sinclair, 1st Baronet (1754–1835), politician and writer on agriculture and finance
- Sir John Sinclair, 3rd Baronet (1825–1912), Scottish politician and landowner
- John Sinclair (MP) (1842–1892), Liberal MP for Ayr Burghs
- John Sinclair, 1st Baron Pentland (1860–1925), Scottish politician
- John Sinclair (environmentalist) (born 1939), Australian environmentalist
- John Sinclair (poet) (born 1941), American poet, activist and radio DJ, subject of John Lennon song
- "John Sinclair", a song by John Lennon on the Some Time in New York City album
- John Sinclair, 3rd Viscount Thurso (born 1953), often referred to as John Thurso, British Member of Parliament for Caithness and Sutherland
- Yasus Afari (John Sinclair, born 1962), Jamaican dub poet
- John Sinclair (German fiction), fictional protagonist of a popular German penny dreadful
- John Sinclair (musician) (born 1952), musician, played with Ozzy Osbourne and Uriah Heep
- John Sinclair (mayor) (1827–1906), mayor of Brisbane
- John Alexander Sinclair (1897–1977), British spy
- John Ewen Sinclair (1879–1949), Canadian politician
- John Gordon Sinclair (born 1962), Scottish actor
- John Howard Sinclair (1848–1924), Canadian politician
- John McHardy Sinclair (1933–2007), British linguist, Professor of English Language
- John West Sinclair (1900–1945), silent-screen actor
- John Sinclair (New Zealand) (1843–1925), New Zealand carpenter, builder, station manager and harbourmaster
- John Sinclair, Lord Murkle (died 1755), Scottish judge
Famous quotes containing the words john and/or sinclair:
“In the years of the Roman Republic, before the Christian era, Roman education was meant to produce those character traits that would make the ideal family man. Children were taught primarily to be good to their families. To revere gods, ones parents, and the laws of the state were the primary lessons for Roman boys. Cicero described the goal of their child rearing as self- control, combined with dutiful affection to parents, and kindliness to kindred.”
—C. John Sommerville (20th century)
“Sinclair Lewis is the perfect example of the false sense of time of the newspaper world.... [ellipsis in source] He was always dominated by an artificial time when he wrote Main Street.... He did not create actual human beings at any time. That is what makes it newspaper. Sinclair Lewis is the typical newspaperman and everything he says is newspaper. The difference between a thinker and a newspaperman is that a thinker enters right into things, a newspaperman is superficial.”
—Gertrude Stein (18741946)