Year 1999 (MCMXCIX) was a common year of the Gregorian calendar that started on a Friday. It is the first year of SpongeBob SquarePants and the year of season 1.

Date Event(s)
May 1 "Help Wanted," "Reef Blower," and "Tea at the Treedome," the pilot episodes, premiered.
The show premiered.
July 17 "Bubblestand" and "Ripped Pants" premiered.
The show officially began.
July 31 "Jellyfishing" and "Plankton!" premiered.
August 7 "Naughty Nautical Neighbors" and "Boating School" premiered.
August 11 SpongeBob SquarePants was picked up for a 2nd season.
August 14 "Pizza Delivery" and "Home Sweet Pineapple" premiered.
August 21 "Mermaid Man and Barnacle Boy" and "Pickles" premiered.
August 28 "Hall Monitor" and Jellyfish Jam premiered.
August 31 SpongeBob SquarePants is announced for a 2nd season.
Heavy Iron Studios was founded.
September 11 "Nature Pants" and "Opposite Day" premiered.
September 17 "Sandy's Rocket" and "Squeaky Boots" premiered.
September 18 "Culture Shock" and "F.U.N." premiered.
October 2 "MuscleBob BuffPants" and "Squidward the Unfriendly Ghost" premiered.
October 28 "Scaredy Pants" and "I Was a Teenage Gary" premiered.
December 31 "SB-129" and "Karate Choppers" premiered.
Community content is available under CC-BY-SA unless otherwise noted.