John Lyon
John or Jack Lyon may refer to:
- John Lyon (botanist) Scottish botanist and plant
- John Lyon (boxer), English boxer
- John Lyon (commissioner), British Parliamentary Commissioner for Standards
- John Lyon (cricketer), cricketer for Lancashire
- John Lyon, Lord of Glamis, Chamberlain of Scotland
- John Lyon, 1st Master of Glamis, see Earl of [Strathmore and Kinghorne]
- John Lyon, [3rd Lord Glamis]
- John Lyon, 4th Lord Glamis
- John Lyon, [6th Lord Glamis]
- John Lyon, 7th Lord Glamis,
- John Lyon, 8th Lord Glamis, Scottish nobleman, judge and Lord High Chancellor of Scotland
- John Lyon (school founder), English founder of Harrow School
- John Lyon, 4th [Earl of Strathmore and Kinghorne]
- John Lyon, 5th Earl of Strathmore and Kinghorne
- John Lyon (poet), Scottish LDS poet
- John Herbert Bowes-Lyon
- John Bowes, 9th Earl of Strathmore and Kinghorne, born John Lyon
- John Lyon, name of several people of Clan Lyon in Scotland
- John Lyon, the real name of singer Southside Johnny
- Jack Lyon, New Zealand politician
- Jack Lyon (footballer), English footballer