John Marston is the protagonist of Red Dead Redemption (2010): a former outlaw forced by federal agents to hunt down the last members of his old gang in exchange for the return of his wife and son. He is voiced by Rob Wiethoff, who played him again in Red Dead Redemption 2 (2018), where John is a younger member of Dutch van der Linde's gang.

John's mother died giving birth to him and his father died when he was a boy. After a few years in an orphanage, he ran away, and Dutch van der Linde took him into his gang and raised him. In the gang he met Abigail, and they had a son, Jack. Those years are the setting of Red Dead Redemption 2.
In 1899, John is a member of Dutch's gang as it falls apart. Arthur Morgan, the protagonist, pushes him to leave with his family. In the epilogue, set in 1907, John tries an honest life, builds a ranch at Beecher's Hope with Uncle and Charles Smith, marries Abigail and hunts down Micah Bell. The final scene shows agents Edgar Ross and Archer Fordham watching his ranch. The prequel's cast is on our Red Dead Redemption 2 characters page.

In 1911, Ross and Fordham take Abigail and Jack and send John after his former gang. Bill Williamson shoots him at Fort Mercer, and rancher Bonnie MacFarlane saves him. With allies in New Austin he storms the fort, then follows Bill and Javier Escuella to Mexico, where he is caught in a civil war. Back home, the agents make him hunt Dutch, who, cornered on a cliff, takes his own life. The mission-by-mission version is on our story missions page.
After the agents release his family, John returns to his ranch, but Edgar Ross leads U.S. Army soldiers in an attack on it. Uncle is killed, John sends Abigail and Jack away, and he walks out to face the soldiers alone. He is shot and killed, and his family buries him. In 1914, after Abigail's death, Jack tracks down the retired Ross and kills him in a duel, in the mission Remember My Family.

John is also the protagonist of Undead Nightmare, a zombie-themed expansion released after the game. Its story is not part of the series' official continuity.
Rob Wiethoff auditioned for a then-untitled game and got the role a few days later. He performed John's voice and movements through performance capture over almost two years for the first game, and returned for Red Dead Redemption 2.
Abigail, Jack, Dutch, Bill, Javier, Edgar Ross and the rest of the cast, with their voice actors, are on our Red Dead Redemption characters page.