John Lyon

John or Jack Lyon may refer to:


 * John Lyon (botanist) (1765–1814) Scottish botanist and plant
 * John Lyon (boxer) (born 1962), English boxer
 * John Lyon (commissioner) (born 1948), British Parliamentary Commissioner for Standards (2008–12)
 * John Lyon (cricketer) (1951–2010), cricketer for Lancashire
 * John Lyon, Lord of Glamis (1340–1382), Chamberlain of Scotland
 * John Lyon, 1st Master of Glamis (died 1435), see Earl of Strathmore and Kinghorne
 * John Lyon, 3rd Lord Glamis (1431–1497)
 * John Lyon, 4th Lord Glamis (died 1500)
 * John Lyon, 6th Lord Glamis (died 1528)
 * John Lyon, 7th Lord Glamis (1510–1558), (forfeit in 1537 but restored in 1543)
 * John Lyon, 8th Lord Glamis (died 1578), Scottish nobleman, judge and Lord High Chancellor of Scotland
 * John Lyon (school founder) (died 1592), English founder of Harrow School
 * John Lyon, 4th Earl of Strathmore and Kinghorne (1663–1712)
 * John Lyon, 5th Earl of Strathmore and Kinghorne (1696–1715)
 * John Lyon (poet) (1803–1889), Scottish LDS poet
 * John Herbert Bowes-Lyon (1886–1930)
 * John Bowes, 9th Earl of Strathmore and Kinghorne (1737–1776), born John Lyon
 * John Lyon, name of several people of Clan Lyon in Scotland
 * John Lyon (born 1948), the real name of singer Southside Johnny
 * Jack Lyon (1898–1941), New Zealand politician
 * Jack Lyon (footballer) (1893–1975), English footballer