Samuel Campbell was a professional hunter in the TV show Supernatural. He is the husband to Deanna Campbell. He is also Mary Winchester's father and John Winchester's father in law. He is the maternal grandfather to Sam and Dean Winchester as well as a temporary vessel of Azazel, the powerful yellow-eyed demon and viceroy of Hell. Samuel greatly inspired the Winchester family as well as his own kin the Campbell family to become detectives of the Supernatural. Samuel Campbell was portrayed by "Dallas"Mitch Pileggi.
In season 4, Dean first met Samuel when Castiel sent him back to the late 70's in order to find out the history behind Sam's demonic abilities. After Dean met his younger version of his mother, Dean later met both of his grandparents. Samuel however, was suspicious of Dean as somewhat hostile towards Dean as he didnt like working with other hunters. They later discovered that that Azazel was in the area making deals and they eventually tracked him down. They attacked him but the demon eventually escaped. Later, Dean told Samuel that he was his grandson while they were talking about how to kill Azazel. Its then discovered that Samuel had possessed Samuel who then knocked Dean unconscious and tied him up. He tuanted Dean asking if he was one of his physic children but then assuming that he had a brother. Azazel then went after Mary and John Winchester as they planned to leave the area. Azazel killed John Winchester and killed his vessel Samuel. Azazel however resurrected John as he and Mary made a deal to visit whatever child she has in 10 years.
Samuel later appeared in Season 6 when he was resurrected by Crowley, who was a demon and the current king of Hell, in order to find Purgatory, hunting and capturing monsters to do so . Crowley promised Samuel that he would bring Mary back. After Sam came back from Hell (however soulless), Samuel and his grandson worked together along with the whole Campell family in order to find Purgatory. However, after reuniting with Dean, things begin to change as Dean discovered after capturing the Alpha Vampire that he was working with Crowley. Because of that, he didn't get along with Dean. During one mission, Samuel later sold his grandsons out to Crowley which forever ruined his relationship with his grandsons. Dean even threatened to kill him once he had the chance. He was later possessed by a monstrous worm known as the Khan Worm and was killed by Sam afterwards.