You know you had ancestors hacking the heads off vamps on the Mayflower.
– Samuel to Dean, 6.01 Exile on Main St.
- Samuel Campbell (Deceased May 1, 1973, revived 2010 and killed 2011) - Husband of Deanna Campbell, father of Mary
- Mary Winchester, nee Campbell (Deceased November 2, 1983, revived 2016 and killed 2019) - Daughter of Deanna Campbell and Samuel Campbell, mother of Sam and Dean, wife of John Winchester.
- Arlene Campbell - Wife of Christian Campbell.
- Mark Campbell (Deceased 2011) - Distant cousin. "Something something, twice removed."
- Johnny Campbell (Deceased 2011) - Unspecified relationship.
- Moishe Campbell (Deceased) - Family member active in 1937; Jewish - one of the New York Campbells mentioned in 6.21 Let It Bleed .
- Jebediah Campbell (Deceased) - Unspecified relationship.
Initially, little is known about the Campbell side of Sam and Dean's family. In 2.04 Children Shouldn't Play with Dead Things Sam and Dean visit Mary's grave which is in Greenville, Illinois. Dean states that the headstone was "put up by her uncle, a man we've never even met."
During 3.02 The Kids Are Alright, following a suggestion from Ruby, Sam checks into Mary's past and finds out that following her death a number of friends and family also died, including Ed Campbell (date unspecified) and Robert Campbell, who died on the 19th of July 2001.
In 4.03 In the Beginning, Dean, having been sent back in time by the angels, discovers that his mother Mary was a hunter. He encounters his grandparents, Deanna and Samuel Campbell, and finds out that they are also hunters who raised Mary to be one. Deanna and Samuel are killed by Azazel. Using Samuel as a vessel, Azazel kills John and eggs Mary into making a deal to bring him back and leave the hunting life behind in exchange for entering her house in ten years.
In going back in time again in 5.13 The Song Remains the Same, Dean, now accompanied by Sam, warn Mary and John about the threat posed by Anna and they retreat to a Campbell family safe house that is outfitted with devil's traps and iron fixtures. It is revealed that John has had little or no contact with any of Mary's family and believed that Samuel died of a heart attack.
Several members of the Campbell family are introduced in 6.01 Exile on Main St., including Gwen, Christian, Mark, and Johnny. Samuel Campbell has been resurrected, and has brought the family, including Sam, together to hunt. Over the course of Season 6, all the Campbells were killed by monsters as they hunted and captured the Alphas for Crowley. Under the Campbell Compound, Dean, Sam, and Bobby find the historic journals of other hunters in the Campbell family, including Moishe Campbell, who investigated H.P. Lovecraft.
- The name Campbell may be a reference to Joseph Campbell's Hero's Journey