Teenage Mutant Ninja Turtles[a] is an American animated television series developed by Ciro Nieli, Joshua Sternin, and Jennifer Ventimilia for Nickelodeon, based on the characters created by Kevin Eastman and Peter Laird.

The series begins with the Turtles emerging from their sewer home for the first time, using their ninjutsu training to fight enemies in present-day New York City.

[5] The series was first announced in October 2009, following the news that Nickelodeon's parent company Viacom had acquired the rights to the Teenage Mutant Ninja Turtles franchise.

Ninjutsu master Hamato Yoshi (Splinter) is carrying his four pet turtles through the streets of Manhattan when he encounters members of an alien race called the Kraang.

During an altercation with these aliens, Yoshi and the turtles are exposed to the Kraang's chemical, called mutagen, which causes organic beings to undergo major physical transformations.

Now teenagers, the turtles (Leonardo, Raphael, Donatello and Michelangelo) venture to the surface for the first time and learn that the Kraang are using the mutagen as part of their plan to take over New York City.

Learning about the Kraang's presence through his adopted daughter Karai, Shredder enters an alliance with the aliens to destroy their mutual enemies in the Hamato Clan.

Kirby is eventually restored to his human form when Donatello manages to concoct another Kraang chemical called retro-mutagen, which causes organic beings to reverse their major physical transformations.

The turtles, April, and Casey are forced to flee to the O'Neil family's summer home in Upstate New York as the Kraang successfully conquers Manhattan.

The group takes refuge at the O'Neil family's summer home in North Hampton in order to recuperate from their loss at the hands of the Kraang and the Foot Clan.

They are successful in finding Splinter and set up a temporary base in the abandoned Antonio's Pizza, and Donatello begins work on new samples of retro-mutagen as the search for Kirby and Karai continues.

The effect of the invasion eventually earns Shredder cemented control of the city's criminal underworld for his efforts to create a mind-control serum meant for the turtles, Mutanimals and Karai.

Despite their best efforts and Shredder violating the Foot Clan's temporary truce with the Turtles by stabbing Splinter during the fight, the ruthless Triceratons activate the Heart of Darkness, a black hole-creating machine which annihilates both the Kraang, the Earth, and everyone on it.

Furthermore, some other crime organizations have been plotting to take over the Foot Clan's territory and a crystal shard of unimaginable power which April received from the alien Aeons during their space adventure is beginning to exert a baleful influence on her.

Using a special mutagen formula made by Stockman-Fly, Oroku Saki recuperates and becomes Super-Shredder in order to take back control of the Foot Clan.

Upon demonstrating the revival ability on Rahzar who fell in an underwater battle against Leatherhead, Kavaxas states that he will need the Kuro Kabuto that contains Shredder's mental energies.

This goes against what Tiger Claw eventually planned when Undead Shredder destroys the Seal of the Ancients which enables Kavaxas to raise the spirits of the Netherworld in order to rule both worlds.

Afterwards, the Turtles face different challenges like the return of Lord Dregg when he collaborates with Newtralizer, being transported to Miyamoto Usagi's reality where they help to protect the pug Kintaro from the evil gray wolf Jei, an adventure featuring an alternate future ruled by mutant animals, and another adventure involving the return of Savanti Romero where he collaborates with Count Dracula to make Earth more habitable for monsters.

On October 21, 2009, Viacom published a press release announcing that it had bought the complete rights of the Teenage Mutant Ninja Turtles franchise from Peter Laird for $60 million, and would be developing a CGI-animated TV series for its Nickelodeon family of channels for broadcast in 2012.

[10] In a May 2011 issue of The Licensing Book, Nickelodeon published subject-to-change concept art of all four turtles, along with artwork from the studio's revamped Winx Club series.

[15] In June, it was revealed that the show's creative team would be led by designer Ciro Nieli and writers J. R. Ventimilia and Joshua Sternin.

The images showed the designs of all four turtles, Shredder, Splinter, a teenage April O'Neil and the Kraang, an alien race that combines elements of both Krang and the Utroms.

[45] Variety has praised the show, saying "...handsomely produced effort, with a strong vocal cast, considerable humor and scads of high-spirited action.

October saw the final release of 2013 with wave six which included two new villains: Spider Bytez and a newly sculpted Shredder figure featuring a removable helmet and cape.

[54] Two unpainted promotional figures were given away at the 2014 San Diego Comic-Con, and Series 1 was released in fall 2014 as blind bags at Kmart and comic shops, and in 2-packs at Toys "R" Us.

On December 6, 2022, Paramount Home Entertainment (Nickelodeon label) released Teenage Mutant Ninja Turtles: The Complete Series on DVD.

[57] In 2013, Nickelodeon published and distributed Rooftop Run developed by Kung Fu Factory for iOS devices such as the iPhone, iPad, and iPod Touch.

[109] Activision also released a Teenage Mutant Ninja Turtles video game based on the series for Wii, Xbox 360, and Nintendo 3DS on October 22, 2013.

[111] In 2017, Raw Thrills developed a beat 'em up arcade game based on the show of the same name, where players can play the turtles and fight villains and boss levels all at once.

[112] On February 27 2024, Raw Thrills and Cradle Games had developed the home console version of the arcade game published by GameMill Entertainment titled Teenage Mutant Ninja Turtles Arcade: Wrath of the Mutants, it was released for Xbox One, Xbox Series X|S, PlayStation 4, PlayStation 5, Nintendo Switch, Microsoft Windows and Steam on April 23 2024.