Teenage Mutant Ninja Turtles III is a 1993 live-action film, the second sequel to the 1990 live-action Teenage Mutant Ninja Turtles film. Full and wide-screen version DVDs were released on September 3, 2002.

April O'Neil finds a scepter and is sent back in time to feudal Japan, and in her place, a man from feudal Japan comes to present New York City with the same scepter, but from his own time. The turtles take the scepter and travel back in time to save April. When the turtles arrive in feudal Japan, many people in a local village understand English because the village has strong trade relations with England. The turtles fight Lord Norinaga and the English trader Walker to stop a war. The movie is sometimes mistakenly thought to have had the subtitle Turtles in Time.

In feudal Japan, a man is seen fighting a group of men, who drag him off. In the present, the Teenage Mutant Ninja Turtles perform a little dance number along with each showing off his fighting style with their weapons in an abandoned subway station to train and get some exercise. After the dance ends, Raphael throws a sai into the speaker, feeling like he and the Turtles have been training for nothing, since no one appreciates the turtles or sees what they do. April O'Neil has been shopping at the flea market in preparation for her upcoming vacation; she brings her friends gifts to cheer them up. Michelangelo is given a colorful lampshade, Donatello is given an old radio, Leonardo is given a book on historical swords and Raphael (who has already walked off in his funk) was to receive a fedora. Having stormed off earlier, he is never formally given it.

For Splinter, she brings an ancient Japanese scepter. Back in feudal Japan, the man who was taken, Kenshin, is being reproached for committing disgrace by his father, Daimyo Norinaga. He leaves his father's presence and drives priests out of a temple. There, he finds the same scepter and reads the inscription: "Open Wide the Gates of Time". Before Kenshin leaves, a British weapons-trader called Walker is introduced, along with his thug Niles. In the present, April is looking at the scepter; it begins to light up and a small bit inside begins to spin. She is then sent back in time and Kenshin forward in time. Upon arrival, April is kidnapped and put in prison. Lord Norinaga wants her to suffer. Back in the present, the turtles make friends with Kenshin and decide to go back in time to get April. They bring Casey Jones back to watch over the lair; four Honor Guards are replaced by the turtles. Back in time, the turtles arrive on horses. Michelangelo can't ride properly and gets kidnapped by outlaws. The scepter was also taken with him. The others go to search for April. When they get to a more populated area they are quickly mistaken for Honor Guards. They find themselves in the jail after following one of Walker's thugs.

After a sloppy rescue, involving another captured person named Whit (who April deems to resemble Casey), they are all left alone without a clue where to go or what to do. Meanwhile, in the present, Kenshin is getting impatient and worried, since after 60 hours, the space-time continuum will be out of phase, meaning the turtles and Kenshin cannot go home, on top of Kenshin having concern for someone back in his own time. Casey introduces him, and the Honor Guards, to hockey. An attack on the turtles, who were again mistaken for the Honor Guards, leads them to Mitsu, leader of the rebellion against Lord Norinaga. They find that Mitsu's village is being burned to the ground and they go to save it. Two men let Michelangelo out of his prison in the same village, thinking him an Honor Guard. He shows them his face and they run away. Michelangelo insists that he is a "beautiful princess in disguise", but he is distracted by their discarded swords. Walker was the one who set the town on fire, in order to find the scepter for a reward and to further the hatred against te daimyo so the war will continue. After being confronted by Michaelangelo and several other villagers, Walker runs. Michaelangelo saves a boy named Yoshi from a fire, then Leo helps by performing CPR, for which the grateful villagers allow them to stay. Anguished by the loss of the scepter, the turtles decide to make a new one.

Walker continues bargaining with Lord Norinaga over the lord buying guns for silver and silk. Norinaga says that once before, demons who resemble the turtles came to stop another ruler's reign. After hearing this, Walker raises the price of his guns to gold. Michelangelo wastes no time teaching some of the people about pizza, but when he bites down, the crust is very hard and impossible to bite, and he decides is will make a better frisbee. Mikey shows signs of being attracted to Mitsu, but he also learns that she and Kenshin share a bond. Raph gets in touch with his sensitive side as well, through the child Yoshi. He becomes very fond of this child, to the point of considering him as an elder brother would consider the younger brother.

Back in the present, the Honor Guards are challenged to a hockey game by Casey. To his dismay, he finds they think hockey consists of beating each other. In the past, the new scepter is completed, only to be broken by Michelangelo and Raphael during an argument over whether or not to stay. Mitsu informs them that Lord Norinaga has guns and will attack the next day. Yoshi, fearing Raph's death, gives him the original scepter. They are overjoyed to see it, but angry at Mitsu because they felt she hid it in order to force them to fight in the war. Mitsu is then kidnapped by Whit, the man they saved alongside April. The turtles go to save her. In the process, they end up freeing all of Mitsu's friends who were captured, leading to a massive battle in the courtyard of Norinaga's palace between the rebels and the daimyo's army. Leonardo defeats Lord Norinaga in a sword duel, comically finishing him by cutting his hair (a disgrace to his status as a samurai), and then trapping him inside of a bell.

Walker now has the scepter, and uses it to his advantage. He tries to escape by tossing it off a rooftop, only to forget his precious birds. The turtles catch the scepter, and Whit, realizing that his name is "lower than scum" in the eyes of the desirable April, finishes Walker by using a catapult, knocking him off in a very long drop to his death in the ocean. The turtles then debate whether to or not to go home, since they are actually appreciated and respected in feudal Japan, unlike New York, where they must hide underground and are feared. The scepter activates, making their decision harder. They all ultimately decide to go, but Michelangelo misses the ride home. After the other turtles return to the present, the Honor Guard who replaced Michelangelo runs off with the scepter. A flash of light occurs– explained to be the closing of the scepter's "gates of time"– and Michelangelo comes back, with the scepter partially smashed and destroyed so that it can no longer be used. He is depressed, until Splinter puts the lampshade on his head as a joke. The turtles end with another dance number.

The film was criticized by fans of the first film who said that it was too cartoony and that the plot was unrealistic and silly, much like the second film. To make matters worse, it also has the least combat. Notably, the turtles only fight three battles, only one of which features all four turtles. Critic Fred Topel called it a "Terrible conclusion of the trilogy." Many fans state that their real complaint is the less-realistic costumes and puppetry of the turtles and Splinter, making it the least well-received film in the series, even though the film was a moderate success.

Soundtrack:
Tarzan Boy - Baltimora
Can't Stop Rockin' - ZZ Top
Rockin' Over the Beat - Technotronic Feat. Ya Kid K
Conga - The Barrio Boyzz
Turtle Jam - Loose Bruce
Fighter - Definition of Sound
Yoshi's Theme - John Du Prez
Turtle Power - Partners in Kryme
Tarzan Boy (Remix) - Baltimora
Rockin' Over the Beat (Remix) - Technotronic Feat. Ya Kid K