Retired hitman John Wick is grief-stricken following the death of his beloved wife Helen. In her absence, he receives one last gift from her—a puppy named Daisy, intended to help him cope with his loss. Wick's mourning is disrupted when he encounters a group of Russian gangsters at a gas station. The group's leader, Iosef, becomes fixated on Wick's vintage Mustang car and offers to buy it. Wick refuses to sell the car, leading an offended Iosef and his henchmen to track Wick down to his home. They break into his house, steal the car, and brutally kill Daisy.

The assault reawakens Wick's suppressed identity as a master assassin, setting him on a path of revenge. The events spark a violent rampage as Wick finds himself re-entering the underworld he left behind. His targets are not just the thugs who wronged him but also those who are connected to them in the criminal world. Wick moves through the shadows of the organized crime syndicate, demonstrating his lethal skills and unwavering determination to seek vengeance. Every encounter brings him closer to confronting the man responsible for his suffering, Iosef's father, Viggo Tarasov, who is a powerful mob boss with vast resources. Wick's quest sets off a chain reaction within the criminal underworld, with bounty hunters and hitmen on his trail as he works his way through the ranks of gangsters to reach his ultimate goal.