|Dates|| 1931 - May 1973 (killed by Azazel)|
2010 (resurrected) - 2011 (killed by Sam Winchester)
|Episode(s)|| 4.03 In the Beginning|
4.04 Metamorphosis (mentioned)
5.13 The Song Remains the Same (mentioned)
6.01 Exile on Main St.
6.02 Two and a Half Men
6.05 Live Free or Twihard
6.07 Family Matters
6.10 Caged Heat
6.16 ...And Then There Were None
6.20 The Man Who Would Be King (mentioned)
Oh, I know a few things. Stick around, I'll show you tricks your daddy never even dreamed of.
– Samuel Campbell, 6.01 Exile on Main St.
Samuel Campbell is a hunter married to Deanna Campbell. He is the father of Mary Winchester and the grandfather of Sam and Dean Winchester, as well as Sam's namesake. Dean meets him when Castiel sends Dean back to 1973 to investigate the origins of Azazel's involvement with his family. He is killed in 1973 by Azazel but later resurrected in 2010. Crowley claims to have resurrected Samuel to capture Alphas in order to determine the location of Purgatory. In 2012, he is possessed by a Khan Worm and killed by Sam.
Samuel is a gruff, suspicious and anti-social man who neither trusts nor likes other hunters, though he grudgingly tolerates Dean as he proves himself capable on the job. After he, Mary and Dean encounter the Yellow-Eyed Demon at the home of Liddy Walsh, one of Mary's friends, the demon possesses Samuel. While using Samuel's meatsuit, Azazel stabs Samuel himself in the gut, snaps the neck of his wife, kills young John Winchester and makes a deal with Mary to bring John, but not her parents, back in exchange for entering Mary's home in ten years (1983).
Samuel isn't mentioned by name, but after Dean informs Sam of what happened in 1973, Sam wonders aloud what the point was to Azazel killing their grandparents (along with the rest of their family), just to give Sam himself Demon Blood.
As Dean had predicted, Mary is upset to see him again because the last time she saw him, Samuel was murdered by Azazel and Dean vanished soon afterward. When John is introduced to Sam, John notes that Mary's father had also been a Sam and Dean says that it's a family name. Dean and Sam tell John that Samuel had been "like a grandpa" to them, and John remarks that Samuel's death was tragic. He is under the impression that Samuel's death had been caused by a heart attack instead of a stab wound.
When Dean is attacked by a djinn, Sam rescues him and reveals he has been back from Hell for a year and hunting with cousins Gwen Campbell, Christian Campbell, Mark Campbell and grandfather Samuel. Samuel doesn't know how he returned from the dead he tells Dean "We're guessing whatever pulled Sam up, pulled me down." He says he wanted to come and get Dean and bring him back to hunting but respected Sam's wishes to leave Dean out of it. Samuel is obviously still adjusting to living in the 21st century he doesn't know the term 'soccer mom' and refers to the the internet as the "intranet".
Samuel knows an antidote to the djinn's poison, which they use on Dean. The Campbells go back to the house Dean is sharing with Lisa and Ben to catch the djinn, but when they realize the djinn are watching the house, Dean suggests they need to leave so the djinn will attack. When they do it is Samuel who helps defeat them.
Samuel receives a call from Sam, who is investigating a string of suspicious child kidnappings. Sam thinks the case may not be their "kind of thing," and Samuel questions his lack of concern for the situation. Sam asks him to find out if the previous victims used the same brand of home security. After rescuing a child from another kidnapping, revealed to be perpetrated by shapeshifters, Sam and Dean bring the child (who is itself the offspring of a shapeshifter) to the Campbells' compound. Despite Dean's suspicions that the Campbells will kill the baby, Samuel says that they will raise it, and let it hunt when it's old enough if it wants to. Samuel presents the child to Christian as an adoptive son.
Moments later, however, an exceptionally powerful shapeshifter arrives in Samuel's form and demands the return of its child. The Campbells attack the shapeshifter but it easily overpowers them and kills Mark despite being shot, stabbed in the heart with a Silver knife, and hit with several elephant tranquilizers. It then takes the baby from Sam and Dean and escapes. Samuel later reveals the monster to be the Alpha Shapeshifter the progenitor of all of the shapeshifters. He is later seen on the phone with someone, promising that he will capture the Alpha Shapeshifter for them.
Samuel seems certain that vampires are involved in the disappearances in Limestone, Illinois because they follow a pattern: this is the fourth town where kids have gone missing and a blood bank van has been jumped and the blood stolen. In this town, the driver of the blood bank van was found with his throat ripped out. Samuel convinces Sam that he and Dean need to investigate further.
After Dean is turned into a vampire, Samuel tells them that the Campbells have a possible cure for vampirism written in Samuel's grandfather's journal, but it can only be used if Dean doesn't drink any blood. Samuel and Sam will gather most of the ingredients for the cure, but Dean has to get the blood of the vampire, Boris, who turned him. Dean insists that he will go into the vampire nest alone: he can sense where they are and he's sure that Sam would just attract attention because he "reeks" like "a walking hamburger." Samuel gives Dean a syringe of dead man's blood to use against Boris, and Dean leaves. Once they're alone, Samuel confronts Sam about his apparent knowledge of the cure. He's worried that Sam purposefully let Dean get infected so that he could get inside the vampire nest and help them capture an Alpha vampire they've been looking for. Sam denies everything, but Samuel doesn't seem convinced. Later, once Dean has Boris' blood, Samuel helps Sam and Dean to create the vampirism cure that saves Dean.
When Dean, Sam, and Castiel learn that Sam no longer has his Soul, they question Samuel about his own resurrection and test him to see if he still has his soul. They learn that his soul is still present, and Samuel reiterates that he doesn't remember anything before waking up alive. After Castiel leaves, Sam and Dean learn that Samuel is preparing to attack the nest of the Alpha Vampire, but Samuel seems reluctant to invite Sam and Dean along. Eventually, Dean convinces him to let them help. Before they leave for the attack, Dean, who is suspicious of Samuel's motivations, tries to break into his office but is waylayed by Christian.
Once they reach the house where the Alpha is hiding, Samuel orders Dean and Gwen to stay back and "sweep any stragglers" they flush out, but Dean is unsatisfied with this and heads around the back of the house, where he sees Samuel, Sam, and the other hunters loading the Alpha Vampire into the back of a van. He waits until he's alone with Sam to confront him about it, and learns that Samuel is taking the creatures he captures somewhere to be interrogated. They activate a GPS tracker in one of Samuel's cell phones so that they can track him to where he takes the Alpha Vampire, and they arrive to find Samuel torturing it, but not getting anywhere. He leaves the room and Sam and Dean take the opportunity to question the Alpha themselves. Eventually, he tells them that Samuel is trying to get information from him about Purgatory and where it is located, and that he's doing it on someone else's orders. Before they can learn more, Samuel, Christian, Gwen, and another hunter interrupt them and hold them at gun point. They're forced to disarm, but then the Alpha escapes and they join forces to try to kill it. Just when things are looking dire, demons show up and take the Alpha away with them, and Crowley appears.
Crowley, as the new King of Hell, had the power to resurrect Samuel and Sam, and he did so because he wanted their help. Crowley reveals that Christian has been possessed for a while and serving as his mole, and that Samuel has been working for him, gathering high-ranking creatures and trying to learn the location of Purgatory because Crowley is interested in "developing" it. He tells them that if Sam ever wants the return of his soul, he and Dean need to help Samuel continue to capture creatures for him.
Castiel tries to locate Crowley with a ritual, but is unsuccessful. He, Dean, and Sam travel to the Campbell Compound and break in so that they can search for clues as to Crowley's whereabouts. Samuel catches them in the act, and when they ask for his help he refuses to tell them how they can find Crowley. Dean asks him why he won't help them and why he's been working for Crowley, and they discover that Crowley promised Samuel that he would resurrect his daughter and Dean's mother, Mary. Dean tells him that it's a bad idea to bring her back from the dead, and Samuel calls Dean a hypocrite. He tells Dean that he never learned how to live without Mary, and leaves.
Eventually, though, Samuel comes around, and he tells them where he's been bringing creatures to Crowley. Using Samuel's information, they find Crowley's prison and Castiel helps them break inside. Unfortunately, Samuel led them into a trap. Samuel uses an angel banishing sigil to get rid of Castiel, and demons grab and imprison Dean and Sam. Dean is horrified by Samuel's betrayal, and he tells Samuel that once he escapes, he's going to find and kill him. Dean is then taken to a room to be fed to ghouls while Sam is left in his cell, and Samuel does nothing to stop it.
Sam and Samuel confided and reveal their true identities as hunters to the town's local police sheriff Roy Dobbs along with his wife Brenda. Eventually after Sam and Samuel figure out that they're dealing with an arachne, Sam suggests that they use Sheriff Dobbs as bait, since he fits the arachne's profile—men in their thirties. However the plan doesn't go well as Roy is taken by the arachne back to her lair, Sam and Samuel eventually follow both the arachne and sheriff Dobbs back to the arachne's lair where they find the rest of the kidnapped men bound in web and also poisoned as well. A fight between Sam and Samuel and the arachne breaks out but it quickly ends with Sam killing the arachne by decapitating her. After Sam kills the arachne Samuel tries and goes to help Roy but Sam quickly declares Roy and the rest of the kidnapped men that have been poisoned are beyond help and shoots all of them killing them all. As they leave the building were the arachne's lair was located Sam tells Samuel that they need to burn the building and destroy all the bodies of sheriff Dobbs and the rest of the kidnapped men. Samuel seems uneasy about Sam's ruthless attitude and is worried about a deep wound on his arm, but Sam puts him and tells him they need to get out of town. Unfortunately as they are trying to leave town Deputy Atkins stops them and asks them were Dobbs is but when he notice the large wound on Sam's arm, he doubts their cover as FBI Agents and tries to arrest them. However before Deputy Atkins can go and arrest both of them Sam beats Deputy Atkins unconscious and they leave town. Unknown to Sam and Samuel, sheriff Dobbs and the rest of the kidnapped men that were poisoned didn't die by Sam's gun shots or by the fire that burned down the building that held the arachne's lair they survived because the arachne's poison turned them all into arachnes.
Samuel is hunting with Gwen, investigating deaths related to a spike in the activity of supernatural creatures. While investigating the murders, they encounter Bobby, Rufus, Sam, and Dean at a cannery. Dean wants to kill Samuel, as he promised he would in 6.10 Caged Heat, but Sam persuades him that Samuel might be useful in the hunt. Gwen tells Dean that she didn't know about Samuel betraying Sam and Dean to Crowley. While they are alone, the creature responsible for the deaths—the Khan worm—infects Dean and uses him to kill Gwen. The creature leaves Dean, and together all the hunters try and work out a way to find and kill it. When Samuel leaves the room, Sam and Dean follow and confront him about what happened with Crowley, but Samuel is not apologetic. He then pulls a gun and tries to shoot them, as he is infected with the worm. They stop him and he escapes, but Sam finds and confronts him alone. Samuel says he will tell Sam about the things he did without a soul, but he advances on Sam and Sam is forced to shoot him.
Bobby and Rufus decide to cut into Samuel's skull to see if the worm is still there but as they do, he comes back to life under the power of the worm. In the ensuing fight he is electrocuted and the worm leaves his body, finally killing him. The worm however infects Bobby.
In flashbacks, when Castiel tells Crowley not to use Dean to help them find Purgatory, Crowley decides to take Samuel "off the bench" and use him in Dean's stead, implying that he had been telling the truth when he said that he had been the one who resurrected Samuel.
- Samuel also appears in the spin-off novel Supernatural: Heart of the Dragon, which reveals that, although his family had been hunters, he only became aware of the "profession" when he witnessed his best friend being attacked by a wraith when he was a teenager, only just managing to kill the creature before it killed him. The novel also mentions that Samuel runs a dry-cleaning business to support his Hunts.