Splinter, often called Master Splinter by his students, is a fictional character from the Teenage Mutant Ninja Turtles comics and all related media.

Splinter is the man-sized rat ninja who, in every rendition, trains the Teenage Mutant Ninja Turtles. He is a master of martial arts (self taught in most canons), and is usually known for raising the four brothers as well. His demeanor is that of an old master, and the respect he commands from the four turtles reflects that.

He is voiced by Nolan North in the video game 'Teenage Mutant Ninja Turtles: Mutants in Manhattan'.