All I see in our family tree is a whole lot of dead.
The diagram above represents the main biological relationships to Sam and Dean.
- Dean Winchester eldest son of Mary and John, brother of Sam, half brother to Adam Milligan
- Sam Winchester youngest son of Mary and John, brother of Dean, half brother to Adam Milligan. After Henry's disappearance in 1958, John may have been raised by a step-father, or adoptive/foster family, as his 'old man' in 1973. No mention has been made of John Winchester's mother.
- Mary Winchester (deceased) - nee Campbell. Wife of John, mother of Sam and Dean.
- John Winchester (deceased) husband of Mary, father of Sam, Dean and Adam Milligan. Son of Henry Winchester
- Kate Milligan (deceased) lover of John Winchester, mother of Adam Milligan
- Adam Milligan (deceased) son of John Winchester and Kate Milligan, half brother to Sam and Dean
- Emma (deceased) daughter of Dean and the Amazon Lydia.
- Henry Winchester (deceased) grandfather of Sam and Dean, and father of John Winchester who disappeared in 1958 only to arrive in 2013 and die at the hands of Abaddon.
- See also Campbell (family) for more relatives on Mary's side of the family tree.
Supernatural is clear that "family don't end with blood" as Bobby once said.
The other familial relationships in Sam and Dean's life are:
- Bobby Singer (deceased) - father figure to the boys from their childhood. He definitely considered Sam and Dean to be his sons - "As fate would have it, I adopted two boys. And they grew up great. They grew up heroes."
- Castiel - Dean said that Castiel is like a brother to him.
- Jessica Moore (deceased) Sam's girlfriend while he was at Stanford. He was about to propose to her when Azazel had her killed by Brady, in order to force Sam back into hunting.
- Amelia Richardson Sam had a relationship with Amelia for a the better part of a year, while Dean was in Purgatory. They lived together in Kermit, Texas. The relationship ended when Amelia's husband Don Richardson, returned after having been presumed killed in action in Afghanistan, and Sam chose to return to hunting over staying with Amelia.
- Lisa Braeden and her son Ben Braeden. Dean had a brief affair with Lisa when he was young, and he looked her up when he was in his last year following his deal with the Crossroads Demon. Dean returned to them following Sam's sacrifice to imprison Lucifer. He lived with them for a year. Eventually, he asked Castiel to wipe him from their memories, due to the danger and violence he felt he bought to their lives.
- Benny Lafitte - After their time together in Purgaotry, Benny and Dean have a close friendship.
- The Impala - Definitely a member of the family.