Dean Winchester was born on January 24, 1979 to John and Mary Winchester. Dean was the couple's first-born child and oldest son, four years older than his younger brother, Samuel Winchester. He drives a black four-door 1967 Chevrolet Impala (which was given to him by his father) and is a fan of classic rock music. He always wears a brass amulet[1] on a long black cloth band necklace. We soon find out that the necklace was given to Dean when he was young, from Sam as a christmas present. It is clearly quite important to Dean, Although the necklace was meant for their dad. (Ackles has claimed in an interview that it is an Egyptian protection amulet, but this has been yet to be proved in an episode) and sometimes different watches and wristbands. He also always wears a silver ring.

From an early age, he was trained by his father John Winchester to hunt down and kill things of the supernatural, but unlike his brother he shows no resentment toward his father for being "raised like a warrior", feeling that after his mother's violent death, his father raised him and his younger brother the only way that he knew how at the time. He seems to prefer "the hunt" to the possibility of a normal life. Due to his father's training, he has several notable advantages for a human: he is an exceptional shot, has knowledge beyond the norm regarding the supernatural, is a skilled fighter, and appears to have some proficiency with melee weapons. He is also the only one allowed to call his brother "Sammy". When giving false names, he frequently gives the names of rock musicians. He also appears to be a fan of Jack Nicholson and possibly watches Oprah. He tends to make light of some of his and Sam's adventures and is known to use crude humor and make sexual innuendos. He is terrified of flying and claims that it is the reason why he drives everywhere. Dean values his family's safety over anything else, even going so far as to kill a demon and its human host in order to save Sam's life.

When Dean was four years old, his mother Mary was killed in his younger brother Sam's bedroom. Twenty-two years later, The Demon responsible for their mother's death kills Sam's girlfriend, Jessica Moore. Together, Dean and Sam go on a road trip to fend off supernatural creatures and search for their father, John, who occasionally leaves new missions for them to complete.

Early in the season ("Skin"), Dean and Sam battle a shapeshifter responsible for a string of brutal murders in the St. Louis, MO area. During the course of the episode, the shapeshifter assumes Dean's form, causing police to believe that Dean is responsible for the murders. However, Dean kills the shapeshifter while it is still in his form, and the authorities officially declare him dead.

In the last episode of this season "The Demon" possessed Dean's father in an attempt to get The Colt for his own. After Dean realises this, "The Demon" pins him and Sam to a wall and reveals that John favors Sam over Dean. the demon also tells Dean that he was responsible for sending his children back to hell, after Dean makes a sarcastic remark about the situation, the demon tortures him, Dean pleads for his father's help before losing consciousness. Sam manages to get free and shoots the demon/John in the leg, releasing the demon from John's body.

The season finale concluded with Sam, Dean, and John escaping from a clash with "The Demon" in Salvation, Iowa. While Sam was driving to a hospital after Dean and John were injured, a demonically possessed driver drove his truck into the Impala, causing massive damage to the car and the Winchesters inside.

All three of the Winchesters survive the wreck, although Dean is more severely injured than his father or brother. In the first episode of Season 2 ("In My Time of Dying"), Dean is in a coma and a reaper, Tessa, tries to convince him to die. In order to save him, John makes a deal with The Demon, trading his life for Dean's. Before he dies, John whispers something in Dean's ear which the audience cannot hear.

Throughout the first half of the second season, Dean struggles with the death of his father, as well as with the knowledge that he was the one who was supposed to have died. Furthermore, he is haunted by his father's last words to him, and at the midpoint of the season, it is revealed that John told Dean that The Demon intends to turn Sam evil, and if Dean can not save Sam, Dean must kill his brother.

During an investigation in Baltimore, MD ("The Usual Suspects"), Dean is arrested in connection with another series of murders. It is revealed that Dean has a rather impressive police record, with charges over the years including credit card fraud, breaking and entering, and grave desecration. Although Sam and Dean are able to prove that the murders were actually committed by one of the detectives on the case, it is unclear whether or not the charges against Dean were ever officially dropped. However, the problem still remains that the authorities have realized that Dean is not dead, as they had previously believed. A team of FBI agents, led by Special Agent Victor Hendrickson catches up with Dean and Sam in Milwaukee, WI ("Nightshifter"), where attempted bank robbery and several more murders are added to Dean's list of supposed crimes. At the end of All Hell Breaks Loose, Part 1, just as he arrives to rescue his younger brother, Sam is stabbed and collapses into Dean's arms. Amidst his brother's pleas to stay with him, Sam dies, leaving Dean alone as the last living Winchester. Dean, believing he failed Sam, is too upset to deal with the crushing blow delivered when Sam died, and in a last ditch effort travels to a crossroads to make a deal with the "crossroads demon" for Sam's life in exchange for his soul. In the end Dean is allowed one year to live and Sam is then resurrected. At first, Bobby is the only one to know of what Dean did, because Sam can't remember anything past when Jake stabbed him and Dean makes up a lie about Bobby patching him up. Bobby yells at him for what he did and Dean pleads with him not to tell Sam what he did, as he knows it will destroy Sam knowing Dean sold his soul.

However, the "Yellow-Eyed-Demon" questions Dean if he is sure what he brought back in Sam is "pure" after Sam unhesitatingly kills Jake, unloading several bullets into his head without any sign of remorse. Sam figures out what Dean did by the end, and Dean tells him not to be mad, that he couldn't let Sam die, not like that. Sam vows to get him out of this, no matter what. At the end of the second season Dean kills 'The Demon' with the Colt freeing his father's soul but during the battle hundreds of other demons escaped their prison and now Dean and Sam must kill all of them, as well as find a way to save Dean from dying in a year's time.

In the season premier of season three "The Magnificent Seven", Dean makes the best of his last year, not worrying about his safety, while Sam tries desperately to find a loophole in the crossroad demons deal. While investigating a case with a family who apparently dehydrated in minutes, Dean, Sam and Bobby team up with a pair of hunters, Tamara and Isaac. they soon realize they are fighting the "Seven Deadly Sins" when Isaac is killed by Gluttony, leaving the Winchesters, Bobby and Tamara alone to fight the centuries old demons. when one of the demons, Wrath, take over Isaacs corpse and tortures Tamara with old memories, we learn that the couple had begun hunting when their daughter was killed by something supernatural. Tamara, unable to listen any more rushes out the door, wiping away the salt. As Tamara beats the Demon!Isaac, the waiting demons rush in to begin battle with the brothers and Bobby.

Bobby is able to exorcise Sloth while he is stuck in a devils trap. Dean, who is fighting with Lust, manages to submerge her in a tub of holy water. Sam on the other hand must deal with Pride, Envy, and Greed. When it seems Sam is out numbered he receives help from a mysterious woman who kills the three demons with a just as mysterious dagger.

Dean, Sam and Bobby salt and burn the dead demons (all but Sloth and Lust, who were exorcised) and say their goodbyes to Tamara. Bobby returns to his car and leaves as well, leaving the Winchesters alone. Sam tells Dean about an idea Ellen gave him about the deal with the crossroad demon, Dean refuses and finally tells Sam there is no way out of the deal, that if they try to get out of it, Sam drops dead. Sam asks how he could have made that deal and Dean tells him that he couldn't live with his brother dead, that he was tired of hunting and that this felt like a way out. Sam tells him he's selfish, to which Dean agrees happily, and that he is "unbelievable" which Dean states is "very true". The episode ends with the Winchester brothers driving off in the Impala.

In the second episode of the season "The Kids Are Alright" we see Dean meeting up with an old "acquantance" almost eight years prior and finds out she has an eight year old son Ben who seems to possess many of Dean's characteristics (from his love of classic rock, to his speech "Dude!" and his love of the ladies). While Dean is questioning whether this is his son or not Sam meets the mysterious blonde again who gives him the hint to search for the people his mother used to know. The brother's figure out the kids are Changlings and defeat the 'mother-of-all-changlings'. Dean is put as ease (somewhat) by his old flame Lisa when she assures Dean Ben isn't his son. And Sam finds out the mysterious blonde is a demon.

The Impala

Dean's trademark black 1967 Chevrolet Impala, bears a Sedgwick County, Kansas (even though they are from Lawrence, Kansas) license plate KAZ 2Y5, a reference to Kansas, the Winchesters' home state, and 2005, the year the show premiered, was passed down to him by his father.

It has been prominently featured on the series, beginning with the teaser of the pilot which shows John Winchester holding his two sons as he sits on the car and watches his house burn. The car is Dean's most prized possession, and he protects it with nearly the same ferocity with which he protects his family. In the pilot episode, the trunk is revealed to hold various weaponry to fight the supernatural. Though it is damaged at the end of "Pilot," it is repaired and the car is featured throughout the first season until a tragic crash at the end of the season finale. The car is in repairs at the beginning of the second season, though Dean beats the trunk of the car with a tire iron in grief at the end of "Everybody Loves a Clown." It appears for the first time fully repaired in "Bloodlust" in an extended sequence to the soundtrack of AC/DC's "Back in Black". Mind-controlled, Dean cheerfully gives the car to Andy Gallagher in "Simon Said," but the brothers soon recover it. Due to the Winchesters' constant battle with avoiding the authorities toward the end of the 2nd season, the plates on the Impala changed. The famous KAZ 2Y5 was taken off and replaced with Ohio plates: CNK 80Q3.

In the Supernatural: Origins prequel comics, John drives Dean and Sam around in a station wagon until the second issue. The Impala is owned by Mary's uncle Jacob, whom John takes along on his first hunt, where Jacob is mortally wounded by a Black Shuck hellhound. An unknown hunter helps John dispose of the body by putting it in the station wagon and rolling it off a cliff into a river, John then takes the Impala as his own car. However this is in contradiction to the Impala appearing at the beginning of "Pilot" but it's more than likely just a mistake by the writers.

Dean tends to use a chromed Colt 1911 with pearl grips, which John is seen using in a flashback. He also uses a sawed off double barrel shotgun when he needs extra firepower. Dean has also been seen with a sniper rifle in the episode "Simon Said." He is shown to posses a large Machete in " Fresh Blood".

As one of the stars of the series Dean has appeared in all of the episodes. However, most episodes are focused on one of the two brothers.