Born in Lawton, Oklahoma and raised in Anaheim, California, Hillenburg became fascinated with the ocean as a child and developed an interest in art.

He was later offered a job on the Nickelodeon animated television series Rocko's Modern Life (1993–1996) following the success of his 1992 short films The Green Beret and Wormholes, which were made as part of his studies.

[2][3][4][8] When he was a year old,[7] the family moved to Orange County, California,[2][4] where his father began a career as a draftsman and designer in the aerospace industry.

"[9][10] His passion for sea life can be traced to his childhood, when films by Jacques Cousteau, a French oceanographer, made a strong impression on him.

An illustration which he drew in third grade, depicting "a bunch of army men ... kissing and hugging instead of fighting", brought him the first praise for his artwork, when his teacher commended it.

[13][22] Hillenburg's first professional job in the animation business was as a director[22][25] on Rocko's Modern Life (1993–1996),[3][22][24] Nickelodeon's first in-house cartoon production.

[39] Murray, who was looking for people to direct Rocko's Modern Life at the time,[22] saw Hillenburg's film and offered him a directorial role on the television series.

[3][4] In particular, the third season episode "Fish-N-Chumps" was co-written and directed by Hillenburg, and involved Rocko, Heffer, and Filburt going on a fishing trip, oblivious to the fact that a pair of anthropomorphic sea creatures are attempting to catch them from underwater; this would foreshadow his later work with SpongeBob.

"[22] During the production of Rocko's Modern Life, Martin Olson, one of the writers, read The Intertidal Zone and encouraged Hillenburg to create a television series with a similar concept.

At that point, he had not even considered creating his own series:[7] "After watching Joe [Murray] tear his hair out a lot, dealing with all the problems that came up, I thought I would never want to produce a show of my own.

As he was developing the show's concept, Hillenburg remembered his teaching experience at the Orange County Marine Institute and how mesmerized children were by tide-pool animals, including crabs, octopuses, starfish, cyclops copepod and sponges.

"[43] In determining the new character's personality, he drew inspiration from innocent, childlike figures that he enjoyed, such as Charlie Chaplin, Laurel and Hardy, Jerry Lewis, Pee-wee Herman, Abbott and Costello, and The Three Stooges.

"[43][50] To voice the central character of the series, Hillenburg turned to Tom Kenny, whose career in animation had begun with his role in Rocko's Modern Life.

[4][44][53] James Poniewozik of Time magazine described the titular character as "the anti-Bart Simpson, temperamentally and physically: his head is as squared-off and neat as Bart's is unruly, and he has a personality to match—conscientious, optimistic and blind to the faults in the world and those around him.

"[56] On the other hand, The New York Times critic Joyce Millman said that the show "is clever without being impenetrable to young viewers and goofy without boring grown-ups to tears.

[33] He directed the film from a story that he conceived with five other writer-animators from the series: Paul Tibbitt, Derek Drymon, Aaron Springer, Kent Osborne, and Tim Hill.

[4] However, Nickelodeon wanted to produce more episodes: "The show was such a cash cow for the station that it couldn't afford not to," storyboard director Sam Henderson observed.

[90] In 1998,[91] Hillenburg formed United Plankton Pictures Inc., a television and film production company, which produces SpongeBob SquarePants and related media.

"[92][93] Various cartoonists, including James Kochalka, Hilary Barta, Graham Annable, Gregg Schigiel, and Jacob Chabot, have contributed to issues of the comic.

"[65] Hillenburg's graphic influences were George Herriman, E. C. Segar, Bill Watterson, Dr. Seuss, Max Fleischer, Chuck Jones, Tex Avery, Bob Clampett, Jay Ward, Jules Engel, Matt Groening, Joe Murray and John Kricfalusi;[108] the latter was inspired to have many close-up shots in several SpongeBob episodes to have grotesque and extremely detailed drawings.

He had also cited Charlie Chaplin, Buster Keaton, Laurel & Hardy, The Three Stooges, W.C. Fields, Jerry Lewis, Jacques Cousteau, Jim Henson's The Muppets and Paul Reubens's Pee-wee Herman.

[113] Hillenburg disclosed to Variety magazine in March 2017 that he had been diagnosed with amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig's disease), though he continued to work on SpongeBob SquarePants for as long as he was able.

[citation needed] The day after Super Bowl LIII, the Dallas Stars of the National Hockey League uploaded on their Twitter page a modified version of the full "Sweet Victory" sequence, in which the band's uniforms were altered from red to green to match the Stars's colors, with the title "The #SuperBowl halftime show fans deserve".

[121][122] In 2019, a spin-off of SpongeBob SquarePants, Kamp Koral, began production, featuring younger versions of the characters attending summer camp.

Former showrunner Paul Tibbitt stated that Hillenburg would have disliked the idea; he commented, "Steve would always say to me, 'You know, one of these days, they're going to want to make SpongeBob Babies.

"[130] The marine demosponge species Clathria hillenburgi, known from mangrove habitats off the coast of Paraíba, Brazil, was named in honor of Stephen Hillenburg.

[131][132] On November 18, 2021, Hillenburg was honored with a bench and historical plaque at his alma mater Savannah High School in Anaheim, California.

[133] Karen Hillenburg specifically chose a bright yellow bench that "she thought perfectly captured her husband's warmth and goofiness".

[134] The memorial was dedicated one day before Savanna High School's 60th anniversary at a school-wide assembly hosted by Hansen and principal Michael Pooley.

The event was attended by Karen and Clay Hillenburg, as well as members of SpongeBob SquarePants' cast and crew including Tom Kenny, Jill Talley, Rodger Bumpass, Bill Fagerbakke, Clancy Brown, Mr. Lawrence, Marc Ceccarelli, and Derek Drymon.