2013 (MMXIII) started on Tuesday of the Gregorian calendar and is the previous year. It is the 2013th year of the Common Era, or of the Anno Domini designation; the 13th year of the 3rd millennium and of the 21st century; and the 4th of the 2010s decade. It will also be the first year in 26 years to have all 4 digits different from each other since 1987.
- January 1: Squid Defense premiered; The SpongeBob Universe was launched.
- January 19: Plankton's Pet premiered.
- March 2: Little Yellow Book premiered.
- March 9: Evil Spatula premiered.
- March 16: Jailbreak! premiered.
- March 24: InSPONGEiac and Karen 2.0 premiered in the British Isles.
- May 25: Safe Deposit Krabs premiered.
- June 6: SpongeBob Moves In! was released.
- October 11: Plankton's Robotic Revenge was released in Europe, and the UK.
- October 14: Don't Look Now and Séance Schméance premiered.
- October 18: Plankton's Robotic Revenge was released in Russia.
- October 22: Plankton's Robotic Revenge was released in North America.
- October 27: The Wiki's first annual Christmas Background Contest began.
- November 11: SpongeBob You're Fired premiered.
- December 8: The wiki's first annual Christmas Background Contest ended.