The Mills Family is a family made up of both biological and adopted members, the majority of which are hunters.
The Mills Family lived for an unknown period of time in Sioux Falls, South Dakota where Jody Mills became the sheriff. She had several run-ins with "town drunk" Bobby Singer and Jody arrested Bobby several times as a result. As a young boy, son Owen Mills died of an unknown cause before any of the family was introduced in the show.
In 2010, during the Apocalypse, Death resurrected the dead of Sioux Falls on Lucifer's orders in order to get at Bobby. Amongst those who were resurrected was Owen Mills. While investigating the resurrected dead, hunters Sam and Dean Winchester first met Jody who prevented their attempts to kill the resurrected townsfolk. Eventually, the resurrected townsfolk turned into zombies, including Owen. The zombiefied Owen killed his father before being killed once more by Sam. With the help of Jody, the Winchesters and Bobby were able to kill the zombiefied townsfolk of Sioux Falls, but Jody lost her husband and son in the process.
Following the zombie outbreak, Jody remained sheriff and became friendlier with Bobby. When the FBI showed up looking for Rufus Turner, Jody helped Bobby cover up his own suspicious activities. She later reluctantly helped Rufus escape police custody at Bobby's request.
While in the hospital for an appendectomy, Jody discovered that her doctor was in fact a monster. After escaping the hospital with the help of Bobby, Jody forged a closer friendship with the Winchesters and Bobby and developed an interest in the supernatural and hunting. Jody began aiding the Winchesters on cases and became a resource they could look to as seen with their instructions to Emily to contact Jody if they failed to return from going after the Alpha Vampire. Jody also began contacting the Winchesters with potential cases she spotted and ones that fell within her jurisdiction such as Vesta's activities.
In 2014, a girl named Alex raised by a "family" of vampires fled out of guilt and ended up in a cell in the Sioux Falls police station. There, Alex was accosted by her "brother" Cody who was killed by Jody. Cody's interaction with Alex revealed the existence of the vampire "family" to Jody who contacted the Winchesters. After Alex was kidnapped back by the vampires, Jody joined the Winchesters in a raid on the vampire nest. Though Alex was turned into a vampire by Celia, she helped Jody kill Celia while the Winchesters killed the rest of the "family" and cured Alex. Alex was then adopted by Jody and while she initially possessed a rebellious attitude, settled into life as Jody's adopted daughter.
In 2015, following the death of her mother, Claire Novak was also adopted by Jody. In 2016, while struggling to adapt to life with Jody and Alex and her desire to hunt, Claire alerted the Winchesters to a possible case that turned out to be vampire Richard Beesome who was after Alex for her role in his being turned and thus the deaths of his family. Richard and a high school student he had turned named Henry who had posed as Alex's boyfriend, attempted to kill Jody, Claire and Alex as part of Richard's revenge. The three were rescued by the Winchesters and Richard and Henry were killed by Dean and Claire. Following the incident, Claire accepted her place in the family more and developed a better relationship with Alex whose desire for a normal life was only strengthened by the encounter with the vampires.
Over the next year, Claire and Alex grew closer as sisters and Alex began to go to nursing school while Claire began hunting on her own after feeling that working with Jody was holding her back too much. After being briefly turned into a werewolf, Claire finally told Jody the truth and though Claire continued hunting solo, she also finally fully accepted Jody as her mother. Jody also continued to expand upon her own hunting exploits, forming a relationship with Canadian hunter Asa Fox before his death. Jody took part in the American hunters assault on the British Men of Letters compound while the British Men of Letters targeted both Jody and Claire for death as American hunters.
- Jody Mills - Matriarch of the family. Jody is the Sheriff of Sioux Falls, South Dakota and has a history of arresting "town drunk" Bobby Singer on a number of occasions. She was also the wife of Sean Mills and the mother of Owen Mills. At some point, Owen died of an unknown cause but was resurrected by Death during the Apocalypse as a zombie. After losing her husband to the zombie outbreak, Jody became aware of the supernatural and became an ally of Bobby and the Winchesters. Following her encounter with a Leviathan, Jody became interested in the hunter lifestyle and aided the Winchesters on a number of cases. Jody ultimately became a hunter in her own right and adopted Annie "Alex" Jones and Claire Novak after meeting them through a case and the Winchesters respectively.
- Sean Mills (deceased) - Husband of Jody Mills and father of Owen Mills. Lost his son to an unknown cause, but Owen eventually returned as a zombie due to Death during the Apocalypse. Killed by his zombiefied son.
- Owen Mills (deceased) - Son of Jody and Sean Mills. Died of unknown causes at a young age but was resurrected by Death during the Apocalypse. Eventually became a zombie along with all of the other resurrected residents of Sioux Falls and killed his father. Killed for a second time by Sam Winchester.
- Annie "Alex" Jones - A young woman who was kidnapped as a child by a "family" of vampires led by Celia. After being used for eight years to feed the "family", Alex had a crisis of conscience and left her vampire "family". After the vampires were killed by Sam and Dean Winchester with the help of Jody Mills, Alex was adopted by Jody. After a rough beginning involving drugs and parties, Alex settled into a more normal life in Sioux Falls and expressed an interest in staying away from hunting and monsters. She is currently going to nursing school.
- Claire Novak - Daughter of Amelia and Jimmy Novak. After losing her father twice as a vessel to the angel Castiel, Claire ended up with her grandmother and then in a series of foster homes after Amelia left to search for Castiel and her husband. After the death of Amelia at the hands of the Grigori Tamiel, Claire was adopted by Jody as she had no living family left. After a rough start, Claire accepted her place in the family with Jody and Alex, but is currently hunting on her own.
- Bobby Singer (deceased) - Once considered the town drunk by Jody, Bobby became a friend and love interest after the zombie outbreak in Sioux Falls during the Apocalypse and the deaths of Sean and Owen. Helped Jody escape the hospital after discovering that her doctor was a Leviathan while Jody helped Rufus Turner escape prison on Bobby's request and while cleaning Rufus's cabin following the destruction of Bobby's house, inadvertently helped him find the Leviathan weakness to borax. Jody and Bobby shared a kiss but the relationship never developed as Bobby died soon after.
- Sam and Dean Winchester - Hunters befriended by Jody, Alex and Claire. Occasionally the Winchesters and members of the Mills Family help each other on hunts. The Winchesters helped to save Alex from Celia's vampire "family", saved Claire from being a werewolf and saved Jody from possession.
- Sioux Falls Sheriff's Department - As the sheriff of Sioux Falls, Jody has her sheriff's department aiding her in her day job though she keeps her deputies out of her hunting.
- Donna Hanscum - Sheriff of Stillwater, Minnesota. Jody and Donna met on a sheriff's retreat and became embroiled in a vampire hunt together. After the end of the case, Jody offered to train Donna in hunting, something she accepted. The two remain friends with Jody sending Alex to meet Donna at a safe house after learning of the threat from the British Men of Letters.
- Asa Fox (deceased) - A Canadian hunter met by Jody while hunting ghouls in the Sioux Falls area. Jody and Asa shared a romantic relationship with each other before Asa's accidental death at the hands of Bucky Sims. Following his death, Jody attended Asa's funeral.
- Other hunters - After getting involved in the world of hunting, Jody developed friendships and alliances between other hunters of her own.
- Mick Davies (deceased) - A decent member of the British Men of Letters who worked with the Winchesters and Claire on a werewolf hunt. After Claire was bitten, Mick helped to rescue her, kill the werewolf and cure Claire of lycanthropy.
- Monsters - Due to both their affiliation with hunters and being hunters themselves, the family has made enemies out of several monsters.
- Zombies - During the Apocalypse, the deceased residents of Sioux Falls were resurrected by Death as zombies. Amongst these were Owen Mills who killed his father after reanimation. Following her son becoming a zombie, Jody helped dispatch the remaining zombies in town.
- Vampires - One of the most preeminent monster enemies of the family are vampires. Sam Winchester has also suggested that Alex may have vampires after her for revenge for her role in Celia's "family".
- Celia's Family (deceased) - A "family" of vampires that kidnapped Alex as a little girl and forced her to help them in luring in men as victims. Killed by Jody Mills and Dean Winchester after which Alex joined the Mills Family.
- Starr's pack (deceased) - A pack of vampires investigated by the Winchesters, Jody and Donna Hanscum. Tried to kill Jody before they were killed by Dean and Donna.
- Richard Beesome and Henry (deceased) - Richard was a man who had fallen victim to Alex's vampire "family" and was turned into a vampire himself. As a result, he accidentally killed his family out of bloodlust and began seeking to get revenge on Alex. With the help of Henry, a popular student he turned into a vampire, Richard sought to destroy Alex's life before killing her. Richard and Henry kidnapped Jody, Alex and Claire and nearly killed them before the two vampires were killed by Dean and Claire.
- Ghouls - Jody Mills once helped hunter Asa Fox on a ghoul case.
- Werewolves - While on a hunt, Claire was attacked and bitten by a werewolf. With the help of the Winchesters and Mick Davies, Justin was killed and Claire was cured. Claire later killed a werewolf pack on her own when saving a little girl.
- Wraith - After Missouri Moseley called Sam for help, Dean and Jody went to her where they learned a friend of hers was killed by a wraith. Jody and Dean head to her son, James Moseley, for help after Missouri had a vision. The wraith kills Missouri and then heads for James and his psychic daughter, Patience Turner. Patience saves James, Jody, and Dean after having a vision of the wraith killing them. The group then kills the wraith.
- Leviathans - Both due to her friendship with the Winchesters and Bobby Singer and random circumstance, Jody came into conflict with the Leviathans. She was also the one who discovered their weakness to borax.
- Annie/Dr. Gaines (deceased) - While recovering from an appendectomy, Jody accidentally discovered that her surgeon was a monster and alerted Bobby. Fearing for her life, Jody fled the hospital with Bobby's help.
- Chet (permanently incapacitated) - While visiting Rufus's cabin following the destruction of Bobby's house, Jody accidentally burned Chet with borax while cleaning. She later disposed of his head at Bobby's request.
- Angels - When attempting to rescue her mother, Claire made an enemy of Tamiel, a Grigori who devoured human souls. Claire killed Tamiel with his own blade and became a hunter.
- Deities - While working alongside the Winchesters, Jody Mills has come into conflict with a few deities.
- Chronos (deceased) - Greek god of time. His victims were brought to the attention of the Winchesters by Jody Mills who helped Sam rescue Dean from 1941, resulting in Chronos' death in the process.
- Vesta (deceased) - Roman goddess of the hearth that targeted residents of Hartford, South Dakota, a town that fell under Jody's jurisdiction as sheriff. Injured Jody before Jody killed Vesta.
- Demons - Members of the family have had troubles with demons both knowingly and unknowingly.
- Crowley (deceased) - As part of his plan to get the Winchesters to stop the Trials of God, Crowley set up a blind date with Jody and proceeded to nearly hex her to death. Once the Winchesters relented, Crowley stopped his hex, sparing Jody's life.
- Jael (exorcised) - A highly sadistic Crossroad Demon who targeted the hunters gathered at the funeral of Asa Fox, including Jody Mills. Jael possessed Jody before being exorcised by Sam, Dean, Max and Alicia Banes and Mary Winchester.
- British Men of Letters - Targeted Jody and Claire for assassination along with all of the other American hunters.
- Mary Winchester (brainwashed; formerly)
- Doctor Hess (deceased)
One of the British Men of Letters elders. During the hunters attack of the Brit's compound, Jody, along with Sam, Walt, and other hunters, corner Hess. When Hess tells Sam of Lucifer's return and Crowley's supposed demise, she says that Sam needs them. When he declines, Hess goes for her gun but Jody shoots her in the head before she can reach it.
- Of the five known members of the family, three have turned into monsters: Owen became a zombie, Alex was briefly turned into a vampire and Claire was briefly turned into a werewolf. Alex and Claire were both cured thanks to the efforts of Sam and Dean Winchester. Jody was also possessed by a demon that was exorcised in part by the Winchesters.