Sly Cooper comes from a long line of master thieves (the Cooper Clan) who only steal from other criminals, thus making them vigilantes. The Cooper family's heirloom, an ancient book by the name The Thievius Raccoonus, records all the secret moves and techniques from every member in the clan. On his 8th birthday, Sly was supposed to inherit the book and learn all of his family's ancient secrets which was supposed to help him become a master thief, however, a group of thugs by the name "The Fiendish Five" (led by Clockwerk, who is the arch-nemesis of the family clan) attack the Cooper household and kills Sly's parents and stole all of the pages from the Thievius Raccoonus. After that, the ruthless gang go their separate ways to commit dastardly crimes around the world. Sly is sent to an orphanage where he meets and teams up and forms a gang with two guys who become his lifelong best friends, Bentley, a technician, inventor and a talented mathematical hacker with encyclopedic knowledge who plays the role as the brains of the gang, and Murray, a huge husky cowardly guy with a ginormous appetite who plays the role as the brawns and the getaway driver of the gang. The three leave the orphanage together at age 16 to start their lives becoming international vigilante criminals together, naming themselves "The Cooper Gang". Sly swears one day to avenge his family and track down the Fiendish Five and steal back the Thievius Raccoonus. Two years later, the Cooper Gang head to Paris, France, to infiltrate Itnerpol (a police headquarters) in order to find the secret police file which stores details and information about the Fiendish Five but during the heist they are ambushed by Inspector Carmelita Fox (towards whom Sly develops a romantic attraction), a police officer who is affiliated with Interpol and is after the Cooper Gang. The gang manage to steal the police file and successfully escapes from her and the rest of the cops. With the secret police file finally in their hands, the Cooper Gang manage to track down the Fiendish Five.

Sly Cooper comes from a long line of master thieves (the Cooper Clan) who only steal from other criminals, thus making them vigilantes. The Cooper family's heirloom, an ancient book by the name The Thievius Raccoonus, records all the secret moves and techniques from every member in the clan. On his 8th birthday, Sly was supposed to inherit the book and learn all of his family's ancient secrets which was supposed to help him become a master thief, however, a group of thugs by the name "The Fiendish Five" (led by Clockwerk, who is the arch-nemesis of the family clan) attack the Cooper household and kills Sly's parents and stole all of the pages from the Thievius Raccoonus. After that, the ruthless gang go their separate ways to commit dastardly crimes around the world. Sly is sent to an orphanage where he meets and teams up and forms a gang with two guys who become his lifelong best friends, Bentley, a technician, inventor and a talented mathematical hacker with encyclopedic knowledge who plays the role as the brains of the gang, and Murray, a huge husky cowardly guy with a ginormous appetite who plays the role as the brawns and the getaway driver of the gang. The three leave the orphanage together at age 16 to start their lives becoming international vigilante criminals together, naming themselves "The Cooper Gang". Sly swears one day to avenge his family and track down the Fiendish Five and steal back the Thievius Raccoonus. Two years later, the Cooper Gang head to Paris, France, to infiltrate Itnerpol (a police headquarters) in order to find the secret police file which stores details and information about the Fiendish Five but during the heist they are ambushed by Inspector Carmelita Fox (towards whom Sly develops a romantic attraction), a police officer who is affiliated with Interpol and is after the Cooper Gang. The gang manage to steal the police file and successfully escapes from her and the rest of the cops. With the secret police file finally in their hands, the Cooper Gang manage to track down the Fiendish Five.