Rufus Turner, portrayed by Steven Williams, is semi-retired hunter who helped Bobby Singer when his wife, Karen Singer, was possessed by a demon. Rufus exorcised the demon and helped cover up Karen's death. It is Rufus who introduced Bobby to the world of the supernatural, and they hunted together for many years until a hunt went wrong in Omaha, Nebraska, and someone important to Rufus died. They became estranged after this. Fifteen years later, Rufus responds to Bobby's request for information on Bela Talbot and helps Dean Winchester locate her in "Time Is On My Side." He returns to active hunting after Lucifer rises and the Apocalypse begins.
Rufus is introduced in the third-season episode "Time Is on My Side" when Bobby, who has not heard from Rufus in about 15 years, receives a phone call in which Rufus alerts him to the whereabouts of Bela Talbot. Dean visits Rufus, even though Sam opposes the idea of hunting for Bela, as they have only a couple of weeks until Dean's deal runs out. Rufus presents Dean with a manila folder on Bela, which gives Dean new and interesting details from her past.
Rufus appears off-screen in "When the Levee Breaks", when he calls Bobby with news of more of the 66 Seals being broken.
In "Good God Y'All", Rufus heads to a town he thinks is under attack from demons, based on omens of a polluted river and a falling star. He calls Ellen, Jo, and Bobby for help. When Sam and Dean arrive, he and Jo have been separated from Ellen. Jo and Rufus capture Sam, thinking he is possessed. Later, Ellen and Dean are able to help break the spell War has over them. Bobby talks on the phone to Rufus about omens that may indicate the appearance of Death, in "The Devil You Know".
In "Weekend at Bobby's", Rufus arrives at Singer Salvage Yard to dispose of the body of an apparently dead Okami. Bobby assists him and helps him evade capture by the FBI. However, the Okami is revealed to still be alive and is subsequently dispatched by Bobby. Afterward, Rufus uses his contacts to uncover information on Crowley's life as a human and later steals a signet ring from a museum which once belonged to Crowley's son as part of Bobby's attempt to regain his soul from the demon. Rufus investigates the same case as the Winchesters and Bobby, in "...And Then There Were None". The group later encounters Samuel and Gwen Campbell, and discover that the monster is a new breed created by Eve, the "Khan Worm." After Gwen and Samuel are killed, Rufus is stabbed by a possessed Bobby. As cremation is not undertaken in the Jewish tradition, Rufus is buried in a Jewish cemetery rather than given a Hunter's funeral pyre. Bobby pours some of Rufus' favorite drink—Johnnie Walker Blue Label—on the grave before taking a drink himself.
After becoming comatose from being shot in the head by Dick Roman, Bobby relives various memories of Sam, Dean, Karen, his family, and Rufus. Remembering Rufus has a traumatic effect on Bobby, and he reveals to Rufus that he is just a memory appearing in Bobby's comatose mind. While initially disbelieving, Rufus accompanies Bobby in a quest through the past in which Bobby confronts his worst memories to momentarily recover from his gunshot wound.
In "Safe House", flashbacks show a case Bobby and Rufus worked together during the fourth season where Rufus called Bobby for help on an apparent haunted house. However, the two eventually realized they were dealing with a being known as a Soul Eater rather than a ghost. Unable to kill the Soul Eater, Rufus painted a sigil that would trap it, but the Soul Eater pulled Bobby's soul out of his body and into its "nest" outside of time and space, using Bobby to attack Rufus. Rufus subdued the possessed Bobby and finished the sigil, trapping the Soul Eater in its nest. He later leaves Bobby the bottle of Johnny Walker Blue found by Sam and Jody Mills in "Time After Time" since Bobby was right about what they were dealing with and brushes off Bobby's concerns about how he escaped the nest.