TMZ - Stephen first revealed his ALS diagnosis in 2017. He's survived by his wife, Karen, and his son, Clay.
Nickelodeon called him "a beloved friend and long-time creative partner to everyone at Nickelodeon, and our hearts go out to his entire family."
Steve created 'SpongeBob' in the late '90s, but he took a circuitous route to his TV and movie success. Hillenburg started out teaching marine biology in Orange County ... but eventually combined that knowledge of ocean creatures with his artistic talent.