Trivia Facts (IMDb)

Actor Mako was announced as the voice of Splinter at the San Diego Comic Con the day before he died.  At least he finished a majority of his performance.

While Leonardo, Raphael, and Donatello all have brown eyes, Michelangelo has blue eyes. According to writer and director Kevin Munroe, this was done to make Michelangelo seem a bit more innocent and younger than the other turtles.

According to writer and director Kevin Munroe on the DVD commentary, the little song that Splinter sings when he enters the kitchen is an old Japanese lullaby that Mako ad-libbed for the scene.

Dedicated to the loving memory of Mako.

During the fight between the Nightwatcher and the monster in the diner, at one point, a refrigerator falls on top of the monster and the music cuts out and the monster is heard making a whimpering noise. This was actually a mistake in the soundtrack, but when the filmmakers saw it, they couldn't stop laughing, and left it in the movie.

Some of the thirteen monsters are based on actual "monsters" from popular myth. The first one that appears in the unfinished building is based on the Yeti, the next one to be captured is obviously the Cyclops, the one that eats a pigeon on a building is clearly modelled on a gargoyle, and the one in the diner brings to mind the Jersey Devil.

The previous movies in the franchise were all live-action. This is the first movie in the franchise in fourteen years. Chronologically, this movie takes place after the first three movies.

According to James Arnold Taylor (the voice of Leonardo) several characters had already been recorded using established voice artists before the Weinstein Company became involved with the film, at which point the characters were re-voiced by celebrities such as Sarah Michelle Gellar (April O'Neil), Chris Evans (Casey Jones), and Patrick Stewart (Winters).

According to the director's commentary on the DVD one of the early drafts of the script had Raphael briefly dying, and Donatello using Winter's technology to bring him back to life. This idea was turned down by Peter Laird, who disliked the idea of having one of the turtles dying.

Karai's first movie appearance. In her original Mirage comic incarnation, Karai was completely unrelated to the Shredder and is actually a member of the Foot Clan's Council of Five, higher rank than the Shredder in the Foot Clan's global hierarchy. It is presumed Karai has the same status in this movie as she is not referred to as the adopted daughter of Shredder as she was in Teenage Mutant Ninja Turtles (2003).

Jim Cummings and Rob Paulsen are the only Teenage Mutant Ninja Turtles actors to make it into this movie since their first TMNT appearances in Teenage Mutant Ninja Turtles (1987).

It was the number one movie in the U.S. on its opening weekend, bringing in $25.45 million.

The movie's lead track "Shell Shock" by Gym Class Heroes originated as a freestyle rap performed at a concert they performed at.

Specific dialogue makes references to the previous live-action movies. In the battle with the Foot Clan, Casey Jones says, "Two minutes for high sticking!" which was one of his lines from his introduction in Teenage Mutant Ninja Turtles (1990). The last line of the movie, spoken by Raphael is, "Man, I love being a turtle!" which has been spoken in each of the previous movies.

Despite this movie taking place in New York City, the prominent landmarks are not seen, only the Brooklyn Bridge. Most of the skyline is fictional.

All of the Generals' names are loosely translated from Spanish: Aguila (means "Eagle"), Gato (means "Cat"), Serpiente (means "Serpent"), and Mono (means "Monkey").

Until Teenage Mutant Ninja Turtles (2014) this was the movie with the largest budget in the franchise.

Splinter's appearance is generally consistent with the previous movies (in which he is depicted as having brown fur), although in this movie, he wears a proper karate gi, as opposed to dirty rags from the previous movies. His right ear is also no longer cut as it was in previous movies. Writer and director Kevin Munroe jokingly responded that Splinter had an otoplasty.

Kevin Munroe, in his opinion, believes he would probably rather re-cast Splinter, instead of having somebody who sounds like Mako, because he doesn't think anybody can really match Mako.

The idea of April O'Neil knowing ninjitsu skills was taken from Teenage Mutant Ninja Turtles (2003) with her receiving some training from Master Splinter, whereas the idea of her wearing a yellow jumpsuit was a nod to Teenage Mutant Ninja Turtles (1987) with her being a reporter wearing a yellow jumpsuit with pockets.

The first entirely animated Ninja Turtle movie.

Splinter use Japanese two times in this movie. The first time is after Leonardo and Raphael's fight at the breakfast table when Splinter walks in to the scene singing in Japanese. One line from his humming/singing that is clearly audible, and sung two times is "Asahi ga noboru" which means "The morning sun rises". The second time he uses Japanese is during the final fight where he holds Winters back, he says "chotto matte", which means "wait a moment".

Marks one of only 2 theatrically released animated films to feature Mako, the other being Rugrats in Paris (2000).

During the first Nightwatcher scene, when the criminals are fleeing, one of the signs on the shops in the background spells out "monro" in hiragana, a Japanese writing system, which is most likely related to writer and director Kevin Munroe.

The film's name instead using the initials of what stand for "Teenage Mutant Ninja Turtles" instead of the full title is what fans usually use to shorten the name.

It is the first Teenage Mutant Ninja Turtles movie made with computer graphics imagery (CGI).

First Teenage Mutant Ninja Turtles film to be presented in the 2.35:1 aspect ratio. All of the previous movies were presented in the 1.85:1 aspect ratio.

Michelangelo is voiced by Mikey Kelley. With Mikey being Michelangelo's shorter name, this marks the first time where a turtle has been voiced by a voice actor with the same name.

One of the arcades at the Turtle's lair features the character Zeus from Imagi's animated television series, Zentrix (2001).

Marco Beltrami composed a score for the movie, but the score was rejected by Warner execs about three and a half weeks before the movie was released. Klaus Badelt was hired to rewrite the score and compose it at the 7th hour. however, still remain in the finished film.

One sequel idea that had already been nixed by Peter Laird had the Turtles go back in time to explore Mayan culture, just as an evil alien race also arrives via teleportation. According to Kevin Munroe, Laird's response was, "Eh, we did it in 1992", a reference to Teenage Mutant Ninja Turtles III (1993).

Chris Evans' first theatrically released animated film.

Josh Peck was considered to voice Casey, a character he would later voice in Teenage Mutant Ninja Turtles (2012).

The only Turtles movie not to be available on iTunes.

In 2023 Warner Bros. sold the rights of this animated film to Lionsgate.

Eugenio Derbez was considered for the role of General Aguila.

This is the last theatrically-released feature length Teenage Mutant Ninja Turtles film to not be distributed by Paramount.

Mikey Kelley previously voiced Michelangelo in a 2001 Rainbow Studios CGI Teenage Mutant Ninja Turtles pilot.

During Raphael's finishing lines, the phrase "we strike hard and fade away into the night" was used. That was also the ending line in the first TMNT comic.

Towards the end of the movie, several items are shown that reference the live-action movies. These include: The Shredder's helmet and staff, a Foot Ninja Mask, the canister of ooze that mutated the turtles and Splinter (labelled TCRI instead of TGRI, though a crack is strategically placed to work either way), the Time Scepter, Walker's hat, Lord Norinaga's helmet, and pieces of the suits of armor worn by the Turtles in Teenage Mutant Ninja Turtles III (1993).