Summary

• The Winchester family is at the center of Supernatural, with Dean and Sam as the most important characters.
• The show introduces various family who contribute to Dean and Sam's story and the overarching narrative.
• The series finale introduces a new Winchester, bringing the total number of family to eight characters.

Supernatural is undoubtedly one of The CW's (or The WB's) most successful television shows, having lasted for 15 seasons and 327 episodes with a dedicated fan base, and the Winchester family was at the center of it all. The two Winchester brothers — Dean and Sam — were the most important characters, and the writers built the show around them as they continuously introduced other family who contributed to Dean and Sam's story. Throughout the dark fantasy series, the audience learned more about the large family and how they all played a role in the show's overarching narrative.

Of course, not every Supernatural character belonged in the Winchester family tree, including Ruby, Castiel, Crowley, Lucifer, and more. However, every family member played a significant role in the television series (and its short-lived spinoff, The Winchesters), from Dean and Sam's grandparents to their long-lost brother. Plus, the series finale surprisingly introduced a new Winchester, bumping up the family member total to eight characters.

Henry Winchester

Henry Winchester, played by Gil McKinney in the CW television series, was Dean and Sam's grandfather and John's father in Supernatural. Henry was a member of the Men of Letters, a top-secret group of people who were the "preceptors, observers, beholders, and chroniclers" of supernatural mysteries. He was not the first Winchester to be welcomed into the society, seeing as his father and grandfather both belonged to the group.

Later in his life, Henry married Millie, and together they had a son named John. Sadly, one of the Knights of Hell attacked the Men of Letters, forcing Henry to travel to the future with the key to the group's headquarters to ensure its safety and to avoid death. Dean and Sam encountered their grandfather (who obviously looked much younger than he should have, thanks to time travel) in Supernatural season 8. They had never met Henry since he disappeared before they were born, but Dean and Sam had a lot of time to get to know their grandfather and learn about the Men of Letters.

Millie Winchester

Unfortunately, Millie Winchester never appeared in the flesh and was rarely mentioned over the course of Supernatural's 15 seasons. All that was known was that she was Dean and Sam's grandmother, John's mother, and Henry's wife. It was unclear what Millie's relationship was like with her son or if she even ever met her grandsons. However, Millie was a main character in the CW show's prequel spinoff, The Winchesters, and she was played by Bianca Kajlich. It was an alternate version of her character from the original series, though, so it's tough to understand what she was like in the central timeline.

John Winchester

Aside from Dean and Sam, John is the third most important Winchester in Supernatural. John was portrayed by Jeffrey Dean Morgan in the dark fantasy television show, and he was Dean and Sam's father who taught them everything they knew about hunting supernatural creatures. Following his father's disappearance, John ed the United States Marine Corps and fought in the Vietnam War. When he returned, John fell in love with Mary Campbell, and they had two sons — Dean and Sam.

Following Mary's death, John dedicated his life to hunting monsters, especially the one that killed his wife, Azazel. As a result, he neglected Dean and Sam, which led to a complicated relationship between the father and his two sons. However, they followed in their father's footsteps and became hunters when they grew up. When Supernatural premiered, John had gone missing, and it was up to Dean and Sam to find him.

Mary Winchester

As aforementioned, Mary Winchester, played by Samantha Smith, was John's wife and Dean and Sam's mother in the CW television series. Unbeknownst to John, when they first met, Mary was a (reluctant) hunter (following in the footsteps of her parents), but she quit hunting when she and John started their family. Before they were married, the demon Azazel killed John, and Mary made a deal with the monster — if he brought John back to life, she would allow Azazel into her home years later.

Azazel held up his end of the bargain and visited the Winchester home shortly after Sam was born. Mary tried to stop the demon, and he killed her. John, Dean, and Sam escaped before Azazel destroyed the home, but the damage had already been done. Mary was gone, and John was determined to avenge her death in Supernatural.

Dean Winchester

Jensen Ackles portrayed Dean Winchester throughout all 15 seasons of Supernatural, and his character, just like Sam's, experienced many highs and lows over the course of the series. Dean was the older of the two brothers, having been born on January 24, 1979, and he oftentimes acted as Sam's surrogate father due to John's obsession with killing Azazel following Mary's death. Dean would go to great lengths to protect his brother, which resulted in his many deaths. Dean was notorious for dying and soon afterward being resurrected, which happened numerous times in the dark fantasy television show.

Sam Winchester

Like Jensen Ackles as Dean, Jared Padalecki starred as Sam Winchester in every season of the CW series. Sam was born on May 2, 1983, a few months before the demon Azazel killed his mother, so he never really knew her (except when he and Dean traveled back in time, of course). Following Mary's death, John taught Sam and Dean how to be hunters, but Sam was hesitant to enter the family business. Consequentially, Sam quit hunting and pursued a law degree. However, the death of his girlfriend pushed Sam to return to hunting alongside his brother. At the end of the day, though, Sam always wanted a normal life away from the supernatural.

Adam Milligan

Dean and Sam learned they had a younger half-brother, Adam Milligan, during Supernatural season 4. Adam, who was played by Jake Abel, was John Winchester's son, who had conceived him with a woman named Kate Milligan. Even though John knew of his son's existence, he never told Adam about Dean and Sam and vice versa. John was not the best father to Adam, so they also had a strained relationship. In season 4, Dean and Sam discovered they had a little brother, but only after ghouls killed Adam and his mother. Adam was later resurrected, though.

Dean Winchester II

The final member of the Winchester family in Supernatural is Dean Winchester II, played by Spencer Borgeson. After Dean's (permanent) death in the series finale of the CW television series, Sam lived his life to the fullest, and he eventually had a son he named after his departed brother. It's unclear who Dean Jr.'s mother was, but it seemed he had a great relationship with his father, given that he was by Sam's bedside when he died of old age in the final Supernatural​​​​​​​ episode.