Sonic the Hedgehog is a popular character originating the eponymous Sega video game series. He also had a long-running Archie Comics series that had been published for 24 years before it finally ended. Sonic's comics were subsequently picked up by IDW Publishing.
While the Teenage Mutant Ninja Turtles Adventures comics were still in print, the Turtles made a cameo appearance in Sonic the Hedgehog #2 in a panel where Michaelangelo tries to make a guest appearance and help Sonic only to be told to scram.
In Sonic the Hedgehog #10, all four turtles were seen in the background during Sonic's trek through the sewers, the brothers comment that they're in the wrong comic book.
In the regular series of Knuckles the Echidna #3, when Knuckles' home Angel Island is on fire, a naked Michelangelo can be seen making a cameo amongst the fleeing animals.
In Sonic Universe #26 when Silver the Hedgehog travels to an alternate timeline he and the Dark Freedom Fighters are seen using a base that resembles the Turtles' Lair.
- Roger Craig Smith (the voice of Pulverizer/Mutagen Man of the 2012 series) is the current in game voice of Sonic the Hedgehog, starting with the game Sonic Colors. Prior to that, Sonic was voiced by Jason Anthony Griffith (who also voiced Miyamoto Usagi in the 2003 series, and Mirage Leonardo in Turtles Forever) in the English Dub of Sonic X, and in games prior to Sonic Colors.
- Rob Paulsen, who voiced as Donatello in the 2012 series and Raphael in the 1987 series, played as a character in Sonic Satam named Antoine Depardieu.
- Jim Cummings who voiced Shredder, Leatherhead and other characters in the 1987 TMNT TV series has also voiced Dr. Robotnik in the SATAM series.
- David Zen Mansley who voiced Bishop in the 2003 series was the also the voice actor of Dark Oak from Sonic X.
- Ben Schwartz, the voice actor behind Leonardo in Rise of the Teenage Mutant Ninja Turtles, voices Sonic in the titular 2020 film.