Col. Roy Campbell (ロイ・キャンベル大佐 Roi Kyanberu Taisa, "Roy Kyanbel" in the MSX2 version of Metal Gear 2), is a commanding officer of FOXHOUND. Introduced in Metal Gear 2, he serves as Solid Snake's primary radio contact in the game and gives information about his mission objective and general gameplay tips.

In Metal Gear Solid, Campbell has more of a personal stake in a new mission, as his niece Meryl Silverburgh is held captive by the revolutionary force Snake is battling. In Metal Gear Solid 2, Campbell is impersonated by "Colonel", Raiden's commanding officer who supports him via codec. When a computer virus starts taking effect on Arsenal Gear, it is revealed that the Colonel is an elaborate A.I. constructed by supercomputer GW from The Patriots in order to manipulate Raiden.

Although he is not involved in the main story, Campbell makes a voice only cameo in Metal Gear Solid 3 during the game over screen scolding Snake for causing a time paradox if the player kills certain supporting characters. He also appears in the Ape Escape crossover minigame "Snake vs. Monkey". In Portable Ops, a young version of Campbell is imprisoned by the FOX unit in South America with Naked Snake (Big Boss). The two escape and begin to recruit disenfranchised enemy soldiers and other allies to their cause. While in the original version of Portable Ops, Campbell cannot be added as a member of Snake's squad, because he had a broken leg at the time and thus only communicates with the player via the radio, he can be added in the expanded version, although only if the player beat Extreme Mode.

In Metal Gear Solid 4, Campbell works for a UN Security Council advisory body that monitors PMC activities. He sends Solid Snake on an unofficial mission to assassinate Liquid Ocelot in order to put a stop to his plans. He provides the means of transportation Snake uses to complete his mission. He is married to Rosemary which causes a rift between him and Meryl (who is now aware that Campbell is her father). However, the marriage is a sham used to fool the Patriots and protect her (and Raiden's) son John.

Outside the main canon, Campbell reprises his role as Snake's reluctant commanding officer in the Game Boy Color game Metal Gear: Ghost Babel, a side-story which serves as an alternate sequel to the events of the original Metal Gear. Campbell, along with Otacon and Mei Ling serves as one of Snake's codec contacts in Super Smash Bros. Brawl. He also makes a brief codec appearance in a minigame in Ape Escape 3.

Roy Campbell is voiced by Takeshi Aono in most Japanese games and Paul Eiding for most English games, while the character in Portable Ops is voiced by Toshio Furukawa in Japanese and David Agranov in English. In Ape Escape 3, he is voiced by Michael McColl.