According to The Hollywood Reporter, Hillenburg graduated from Humboldt State University in 1984 with a bachelor's degree in Natural Resource Planning and Interpretation, with an emphasis on marine resources. Variety reported that he taught marine biology at the Orange County Marine Institute (now the Ocean Institute) in Dana Point, California, later taking his talent in writing and illustration and love of the sea to create "SpongeBob SquarePants."

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First airing on Nickelodeon on May 1, 1999, more than 250 episodes of the cartoon series have aired to date. Hillenburg left the show after its third season to write, direct and produce “The SpongeBob SquarePants Movie,” which was released in 2004 and grossed $140 million globally. Hillenburg returned to the show in 2015 as an executive producer, also taking on that role for 2015’s “The SpongeBob Movie: Sponge Out of Water.”

Hillenburg is survived by his wife of 20 years, Karen Hillenburg; son Clay; mother Nancy Hillenburg; brother Brian Kelly Hillenburg and his wife Isabel and nieces Emma and Hazel.