2013 (MMXIII) started on Tuesday of the Gregorian calendar.
| Date | Event(s) | |
|---|---|---|
| January 1 | Squid Defense premiered. | |
| January 8 | The Great Train Mystery was re-released. | |
| January 9 | SpongeBob Comics No. 16 was released. | |
| January 15 | Extreme Kah-Rah-Tay was released. | |
| January 19 | Plankton's Pet premiered. | |
| February 13 | SpongeBob Comics No. 17 was released. | |
| February 18 | Disorder in the Deep was released. | |
| March 2 | Little Yellow Book premiered. | |
| March 9 | Evil Spatula premiered. | |
| March 11 | The Good Krabby Name, Move It or Lose It, Patrick-Man!, and Gary's New Toy premiered on Canada's YTV. | |
| March 12 | The Complete Eighth Season was released. | |
| March 13 | SpongeBob Comics No. 18 was released. | |
| March 16 | Jailbreak! premiered. | |
| March 22 | Eek, an Urchin! premiered in Canada. | |
| March 24 | InSPONGEiac premiered in the British Isles. | |
| April 10 | SpongeBob Comics No. 19 was released. | |
| April 12 | Plankton's Diary: Karen premiered. | |
| April 19 | SpongeBob SquarePants 4-D: The Great Jelly Rescue! was opened. Plankton's Diary: Evil Laugh premiered. | |
| May 2 | Sweet & Sour Squidward was released. | |
| May 4 | SpongeBob Comics Freestyle Funnies 2 was released. | |
| May 8 | SpongeBob Comics No. 20 was released. | |
| May 25 | Safe Deposit Krabs premiered. | |
| June 6 | SpongeBob Moves In! was released. | |
| June 9 | Plankton's Diary: Plankton's Evil Plan premiered. | |
| June 12 | SpongeBob Comics No. 21 was released. | |
| June 19 | SpongeBob Comics Annual Super-Giant Swimtacular #1 was released. | |
| July 3 | SpongeBob Marbles & Slides was updated for the tenth time. | |
| July 10 | SpongeBob Comics No. 22 was released. | |
| August 5 | SpongeBob on Tour was released. | |
| August 9 | SpongeBob Diner Dash was updated for the fourth time. | |
| August 14 | SpongeBob Comics No. 23 was released. | |
| September 2 | The SpongeBob's Best Day Off Ever and FairlyOke SongPants Day marathons occurred. | |
| September 11 | SpongeBob Comics No. 24 was released. | |
| October 9 | SpongeBob Comics No. 25 was released. | |
| October 11 | Plankton's Robotic Revenge was released in Europe. | |
| October 14 | Don't Look Now and Séance Shméance premiered. | |
| October 15 | It's a SpongeBob Christmas! Blu-ray was released in America. | |
| October 18 | Plankton's Robotic Revenge was released in Russia. | |
| October 22 | Plankton's Robotic Revenge was released in North America. | |
| October 28 | The Complete Eighth Season was released in the UK. SpongeBob Diner Dash was updated for the fourth time. | |
| November 11 | SpongeBob You're Fired premiered. | |
| November 13 | SpongeBob Comics No. 26 was released. | |
| November 14 | SpongeBob Marbles & Slides was updated for the 11th time. | |
| December 11 | SpongeBob Comics No. 27 was released. | |