John

There are multiple characters with the first name of "John", "Jon" or "Jonathan" in Call of Duty:
*John Bellomy - A character from Call of Duty: Finest Hour.
*John Davis - A playable character from Call of Duty 2.
*John Jackson Smith - A character from Call of Duty 2: Big Red One.
*Jon Elliot - A character from Call of Duty 2: Big Red One.
*Johnathan Callard - A character from Call of Duty 3.
*John "Soap" MacTavish - A character from Call of Duty 4: Modern Warfare, Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3 and other various Call of Duty games.
*John Price - A character Call of Duty 4: Modern Warfare, Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3 and other various Call of Duty games.
*Jonathan Shepherd - A playable character from Call of Duty: Roads to Victory.
*John "Banana" - A playable character featured in Verrückt from Call of Duty: World at War and mentioned in Call of Duty: Black Ops, Call of Duty: Black Ops III and Call of Duty: Black Ops 4.
*John F. Kennedy - A character featured in Call of Duty: Black Ops, playable in "Five" and real life US President.
*Jonathan Price - A character mentioned in Call of Duty: Black Ops.
*Jonathan Irons - A character featured in Call of Duty: Advanced Warfare.
*John - A multiplayer character in Call of Duty Online.
*John Taylor - A character from Call of Duty: Black Ops III.
*John Alder - A character from Call of Duty: Infinite Warfare.
*John P. Andrews - A character featured in a Divisions video from Call of Duty: WWII.
*Jonathan Warwick - A playable character featured in Dead of the Night from Call of Duty: Black Ops 4.
*John Doe - A playable Zombie featured in Blackout from Call of Duty: Black Ops 4.
*John Price - A playable character introduced in Call of Duty: Modern Warfare.
*Johnny "Soap" MacTavish - A playable character introduced in Call of Duty: Modern Warfare.
*John Baker - A playable character featured in Call of Duty: Black Ops Cold War and Call of Duty: Warzone.
*John Rambo - A playable character featured in Call of Duty: Black Ops Cold War, Call of Duty: Warzone and Call of Duty: Mobile.
*John McClane - A playable character featured in Call of Duty: Black Ops Cold War, Call of Duty: Warzone and Call of Duty: Mobile.
*John Miller - A character featured in Call of Duty: Vanguard.
*John Doe - A character featured in Call of Duty: Modern Warfare III and Call of Duty: Warzone 2.0.
*John Blanchard - A character in the Zombies mode of Call of Duty: Modern Warfare III and Call of Duty: Black Ops 6.
There are also real people involved in the Call of Duty series with the first name of "John" or "Johnny":
*Johnny Christ - A real life musician appearing in Call of Duty: Black Ops II
*John Rafacz - Director of Communications at Treyarch.
*John Dobbie - Former Environment Artist at Infinity Ward.
*John Sahas - Former Senior Multiplayer Designer at Infinity Ward.
*John Harries - Former Senior Software Engineer at Infinity Ward.