 SpongeBob SquarePants is a fictional character , the protagonist of the American animated television series of the same name . He is voiced by actor and comedian Tom Kenny , and first appeared on television in the series ' pilot episode on May 1 , 1999 . SpongeBob SquarePants was created and designed by cartoonist and marine biologist Stephen Hillenburg shortly after the cancellation of his previous series, Rocko's Modern Life . Hillenburg envisioned SpongeBob as a sponge, and the character became the main character of the series. Unterscheidung von SpongeBob SquarePants und Spongebob Squarepants. SpongeBob SquarePants ist