The Foot Clan (also known simply as the Foot) is a fictional ninja clan in the Teenage Mutant Ninja Turtles franchise, serving as the main antagonists. It is led by the devious Shredder and his second in command Karai. The Foot Clan was a parody of the criminal ninja clan The Hand in the Daredevil comics published by Marvel Comics. In addition to the obvious similarity in their names, both clans originate from Feudal Japan, practice ninjutsu and black magic, and have become powerful global organized crime rings who are familiar with multiple illegal activities such as drug smuggling, counterfeiting of money, gunrunning, murder, assassination, computer hacking, theft, and terrorism.

In the original Teenage Mutant Ninja Turtles series by Kevin Eastman and Peter Laird, the Foot Clan was founded in Feudal Japan by two men named Sato and Oshi. In issue #47, the Turtles and Renet traveled to a time prior to the Foot's creation, with Raphael inadvertently teaching Sato and Oshi about Ninjutsu without knowing their identities.

The Foot Clan are the most feared clan of warriors and assassins in Japan. Both Hamato Yoshi and Oroku Nagi were members until Nagi attacked Yoshi's love Tang Shen and Yoshi killed Nagi. Dishonored, Yoshi and Shen fled to New York City, while Nagi's younger brother Oroku Saki was adopted by the clan and trained to become a ninja. When he was ready, Saki was sent to America to head the New York branch of the Clan. Karai, a clan leader from Japan, enlists the Turtles to stop the clan war and enact a peace treaty.

The 1987 series and the spin-off TMNT Adventures comics share a similar continuity, and thus the same version of the Foot Clan. The Foot is an ancient ninjutsu clan, founded in Japan in 1583. Shredder, followed by the Turtles and Splinter, went back and forth in time to try to kill the creator of the Foot Clan. In 1583, Shredder's ancestor Oroku Sancho led a small group of samurai, and Shredder offered to help him find magical artifacts that would give him power and wealth beyond his wildest dreams. Meanwhile, Splinter's ancestor Hamato Koji had been sent to find the same artifacts and did find them with the help of his descendant and the Turtles. One of the artifacts released a dragon, which headed for nearby villages; Splinter and Koji went to stop it while the Turtles went to fight Shredder. Sancho's men captured the Turtles and were about to execute them when Koji arrived, riding the dragon, which he had tamed. Seeing this, Sancho fled in fear, and Koji offered to lead Sancho's men and teach them the ninjutsu art of Shibana-Sama, founding the Foot Clan, so named for the footprint of the dragon in which he stood as he made his speech.

In 1960s Japan, both Oroku Saki and Hamato Yoshi were part of the Clan. Saki framed Yoshi for trying to murder a visiting sensei and had him exiled to New York City, thus clearing the way to take over the Foot Clan. He then proceeded to turn the Foot Clan into an army of criminals. Over the years, Saki, who became known as Shredder, moved to the US, allied with the alien warlord Krang, and replaced the human Foot Ninja with robotic Foot Soldiers.

The Foot Clan's logo is a drawing of a right foot, and the Foot Soldiers wear purple and black uniforms featuring the logo on their foreheads. The Foot logo can also be seen on the Technodrome.

In the IDW Publishing adaption, the Foot Clan existed since the time of feudal Japan and was founded by ronin Takeshi Tatsuo who had been betrayed by his master. The sorceress Kitsune helped Tatsuo recover from the severe wounds he had suffered in the assassination attempt. The name of the clan was created by the bloody footprint of Tatsuo, whose leg was completely healed by Kitsune.

When Tatsuo was betrayed by his clan are learning that he made a pact with a magician, his mind was born again in the son of his murderer Oroku Saki, the uprooting of the reawakening of his old memories powered over the communities and with Kitsune's counsel the Foot was revived in modern times.