2009 (MMIX) was a common year of the Gregorian calendar that started on a Thursday.

The year aired the final episode of season 5, the second half of the 6th season and very early episodes in season 7

Date Event(s)
January 1 "Club SpongeBob" and "My Pretty Seahorse" premiered in Poland.
January 4 "Pressure" and "The Smoking Peanut" premiered in Poland.
January 8 "Procrastination" and "I'm with Stupid" premiered in Poland.
January 10 "Nasty Patty" and "Idiot Box" premiered in Poland.
January 15 "Mermaid Man and Barnacle Boy IV" and "Doing Time" premiered in Poland.
January 18 "Wet Painters" and "Krusty Krab Training Video" premiered in Poland.
January 21 "As Seen on TV" and "Can You Spare a Dime?" premiered in Poland.
January 24 "Snowball Effect" and "One Krabs Trash" premiered in Poland.
January 27 The DVD, Spongicus, was released.
"No Weenies Allowed" and "Squilliam Returns" premiered in Poland.
January 31 "SpongeBob Meets the Strangler" and "Pranks a Lot" premiered in Poland.
"Slide Whistle Stooges" premiered in Australia.
February 4 Lux Interior died.
February 5 "Krab Borg" and "Rock-a-Bye Bivalve" premiered in Poland.
February 16 "Shuffleboarding" and "Slide Whistle Stooges" premiered.
February 17 "Cephalopod Lodge" premiered.
February 18 "Grandpappy the Pirate" premiered.
February 19 "Professor Squidward" premiered.
February 24 SpongeBob vs. The Big One: Beach Party Cook-Off, SpongeBob's Greatest Hits, and Good Ideas... and Other Disasters were released.
March 3

SpongeBob vs. The Big One DVD was released.
SpongeBob vs. The Big One: Beach Party Cook-Off was released.
The Happy Squared Double Pack was released for the PlayStation 2.

March 10 Surf's Up SpongeBob! was released.
March 16 "Sand Castles in the Sand" premiered.
March 17 "Toy Store of Doom" premiered.
March 18 "Pet or Pests" premiered.
March 19 "Komputer Overload" premiered.
March 20 "Choir Boys" premiered.
March 30 "Patty Caper" premiered in Australia.
April 17 "SpongeBob SquarePants vs. The Big One" premiered.
April 19 "SpongeBob SquarePants vs. The Big One" premiered in Poland.
April 20 "SpongeBob SquarePants vs. The Big One" premiered in Canada.
April 22 SpongeBob & You Save the Big Blue, Educate and Activate, Educate and Activate 2, Separation Anxiety, Surfing Dreams, and SpongeBoard premiered.
May 1 The SpongeBob SquarePants series became 10 years old.
May 25 SpongeBob StarPants was released.
May 28 "Friend or Foe" premiered in Poland.
June 1 "Shell Shocked" premiered.
June 2 "Pineapple Fever" premiered.
June 3 "Single Cell Anniversary" premiered.
June 4 "Squid's Visit" premiered.
June 5 "Gullible Pants" premiered.
June 9 SpongeBob RoundPants and 10 Happiest Moments were released.
June 11 "The Original Fry Cook" and "Night Light" premiered in Poland.
June 23 Happiness to Go! was released.
June 25 "Rise and Shine," "Waiting," and "Fungus Among Us" premiered in Poland.
July 9 "Spy Buddies," "Boat Smarts," and "Good Ol' Whatshisname" premiered in Poland.
July 10 "What Ever Happened to SpongeBob?" premiered in Poland.
July 17 "To SquarePants or Not to SquarePants" premiered.
The Ultimate SpongeBob SpongeBash began.
July 18 "Chum Caverns" premiered.
July 19 The Ultimate SpongeBob Sponge Bash ended.
"Goo Goo Gas," "No Hat for Pat," "I ♥ Dancing," "Someone's in the Kitchen with Sandy," "Chum Bucket Supreme," "Growth Spout," "Tentacle-Vision," "The Inside Job," "Stuck in the Wringer," and "Overbooked" premiered.
July 21 The DVD, To SquarePants or Not to SquarePants, was released.
July 23 "New Digs" and "Krabs à la Mode" premiered in Poland.
August 6 "Roller Cowards" and "Bucket Sweet Bucket" premiered in Poland.
August 27 "Money Talks," "SpongeBob vs. The Patty Gadget," and "Slimy Dancing" premiered in Poland.
September 3 Comic Crazy! was released.
September 4 "House Fancy" and "Krabby Road" premiered in Canada.
September 8 The Great Escape was released.
"Walking Small" and "Squilliam Returns" premiered in the Republic of Cyberia.
September 10 "The Krusty Sponge" and "Sing a Song of Patrick" premiered in Poland.
September 22 The First 100 Episodes was released.
September 30 Nickelodeon Japan shuts down on the same day Nickelodeon changed their logo internationally due to declining viewership. So after the channel was removed from the air, the series moved to Animax and NHK.
October 1 "Goo Goo Gas" and "Le Big Switch" premiered in Poland.
October 12 SpongeBob Diner Dash was released.
October 15 "Atlantis SquarePantis, Part 2" premiered in Poland.
October 19 FrankenBob's Quest and FrankenBob's Quest Pt 2 were released on
October 24 "The Curse of Bikini Bottom" premiered.
October 26 The game, SpongeBob's Truth or Square was released in North America.
October 29 "Blackened Sponge" and "Mermaid Man vs. SpongeBob" premiered in Poland.
November 5 "Atlantis SquarePantis, Part 1" premiered in Poland.
November 6 "Truth or Square" premiered.
November 10 The DVD, SpongeBob's Truth or Square was released.
November 14 "Truth or Square" premiered in Poland.
November 26 "The Inmates of Summer" and "To Save a Squirrel" premiered in Poland.
November 27 "Greasy Buffoons" and "Model Sponge" premiered.
December 3 "Pest of the West" premiered in Poland.
December 8 Balloons, Juice Man, Traffic, and The Outfit premiered.
Season 6 Volume 1 was released.
December 10 "20,000 Patties Under the Sea" and "The Battle of Bikini Bottom" premiered in Poland.
December 17 "The Two Faces of Squidward" and "SpongeHenge" premiered in Poland.
December 26 Merry Mayhem! and Jingle Brawl was originally released on
December 31 "Banned in Bikini Bottom" and "Stanley S. SquarePants" premiered in Poland.