Dean Winchester (Jensen Ackles) is a hunter of supernatural creatures. Along with his younger brother Sam (Jared Padalecki), Dean travels across America in his beloved 1967 Chevrolet Impala, hunting ghosts, monsters and demons which threaten the lives of innocent people.
When Dean was four years old, a demon named Azazel (Fredric Lehne, various others) killed his mother Mary (Samantha Smith) and set fire to the Winchester house. After the fire, John Winchester (Jeffrey Dean Morgan) took Dean and infant Sam with him as he began a life on the road in search of answers and revenge. Grown up and continuing the family business, Dean spends his time killing monsters, chasing girls and wise-cracking though not necessarily in that order.
At the start of the series, Dean travels to California to meet Sam, who is attending college at Stanford and living with his girlfriend, Jess (Adrianne Palicki). Dean convinces Sam to help him find their father, who has gone missing during a hunt, and the two set out together for the first time since Sam left the family to go to college. When the brothers return from their unsuccessful hunt for their father, they find that a demon has killed Jess in much the same way as their mother. Once again in search of answers, the brothers set out together to find their missing father.
When the brothers eventually find their father, he reveals that his sudden absence is due to the fact that his hunt for the demon Azazel is nearly at an end. Eager to help his father and be a good son, Dean agrees to help him search for a mystical gun made by Samuel Colt, which is able to kill any creature.
After the Winchesters escape a fight with Azazel, their car is hit by a truck driven by a demon possessed man. Although Sam and John receive only minor injuries, Dean is not expected to survive. In order to save the life of his oldest son, John gives Azazel his life, soul and the Colt in exchange for Dean's health.
With his father's sacrifice hanging over his head, Dean vows to see his family avenged, and continues to hunt Azazel, who has taken a special interest in Sam. Mirroring his father's earlier sacrifice, Dean later offers up his soul as payment after one of Azazel's followers kills Sam. Reunited for the time being, the brothers succeed in stopping Azazel's plan to open a gate to Hell; Dean shoots and kills Azazel, finally avenging the deaths of his parents.
In the following year, Dean and Sam spend their time attempting to send the few demons who escaped through the gate back to Hell, whilst also attempting to break Dean of the deal that will resign his soul to Hell in one year.
After the two fail to save his soul, a ferocious pack of Hell Hounds attack and kill Dean during a climactic confrontation with the demon Lilith (Sierra McCormick, various others). Four months after Dean's death, the angel Castiel (Misha Collins) drags Dean's soul out of Hell and revives him so that Dean can prevent Lilith from bringing about the Apocalypse.
Although Dean and Sam battle both their own growing troubles and an army of demons valiantly, they are unable to stop Lilith from releasing Lucifer (Mark Pellegrino) and starting the Apocalypse. Stuck in a war being waged between Heaven and Hell, Dean and Sam attempt to trap Lucifer back in his prison using the rings belonging to the Four Horsemen of the Apocalypse.
Overall Dean is very devoted to his mother and younger brother and is a defender of humanity. He has only been in love once and does not have many female friends. His dedication to preserving his family's safety is the most important quest for Dean, and it is epitomized by the sacrifice of his own life to resuscitate his brother.
"I'm not gonna die in a hospital where the nurses aren't even hot." Season 1, Episode 12
"We know a little about a lot of things; just enough to make us dangerous." Season 2, Episode 8
"What do you want me to do, Sam, huh? Sit around all day writing sad poems about how I'm going to die? You know what, I've got one. Let's see, what rhymes with "Shut up, Sam"?" Season 3, Episode 7
"Honestly, I think the world's going to end bloody. But it doesn't mean we shouldn't fight. We do have choices. I choose to go down swinging'." Season 3, Episode 12