The Shredder is a supervillain and the main antagonist of the Teenage Mutant Ninja Turtles media franchise created by Kevin Eastman and Peter Laird. The character debuted in the Mirage Studios comic book Teenage Mutant Ninja Turtles #1 (May 1984), and has since endured as the archenemy of the turtles and their master Splinter.

The Shredder is usually depicted as the alter ego of Oroku Saki, the ruthless leader of a criminal ninja organization known as the Foot Clan. A suit of armor equipped with metal blades and tekko-kagi, loosely based on that of a samurai, serves as the Shredder's visual motif.

In 2009, IGN ranked Shredder as the 39th-greatest comic-book villain of all time. The character has been featured in almost every media adaptation of the TMNT franchise, having been portrayed in live-action films by James Saito, François Chau, Tohoru Masamune, and Brian Tee. James Avery, Scottie Ray, Kevin Michael Richardson and Hoon Lee are among the actors who have voiced the character in animated films and television shows.

Kevin Eastman got the idea for the Shredder's armor from large trapezoidal cheese graters which he envisioned on a villainous character's arms. He then said, "Could you imagine a character with weapons on his arms like this?" Peter Laird suggested the name The Shredder. Although Shredder is often depicted as the main antagonist in most TMNT adaptations, it was never the creators' intention to be the case in his original inception in the Mirage Comics:

In truth, though many TMNT fans who became fans via the first animated series see Shredder as a REALLY important part of an ongoing, long-running battle with the Turtles, I don't think Kevin or I ever did. Yes, he was an important part of their history, and they probably would not have come into existence without his involvement in their world (or more accurately Splinter's world)... but that's about it. Other than bringing Shredder back for "Return to New York" (and the few issues preceding that set that arc up), I never missed him in any of the other TMNT books I worked on.
—Peter Laird

In the original comic books from Mirage Comics, Oroku Saki had an elder brother by the name of Oroku Nagi, who had been killed by fellow ninja Hamato Yoshi (the owner of Splinter, the Turtles' mentor) in a feud over a woman named Tang Shen, resulting in Yoshi fleeing with Shen to the United States.

Angered by the death of his elder brother, Saki joined the Foot Clan and trained to be a ninja. He quickly became one of their deadliest warriors and rose up the ranks and was chosen to lead the Foot's American branch. Operating in New York under the name of The Shredder, Saki used the opportunity to avenge his brother by killing Yoshi and Shen. Under Saki's leadership, the Foot participated in variety of criminal activities, including drug smuggling, arms running, and assassination.

Fifteen years later, Shredder was challenged by the Ninja Turtles, who were the result of an accident exposing four ordinary turtles to radioactive waste. They were trained by Yoshi's pet rat Splinter, who had also been mutated by the same substance, to avenge his former master. After a lengthy rooftop battle where Shredder seemed to be winning, Leonardo managed to plunge his sword through Shredder's torso. Defeated, he was offered the opportunity to commit seppuku (ritual suicide), but refused and detonated a thermite grenade, in an attempt to take their lives alongside his own. But at the last second, Donatello used his bō to knock Shredder off the building to his death.