List of post-release content in Splatoon 2

Post-release content is additional content released for Splatoon 2 after the game's release date. Nintendo frequently released new weapons, stages, modes, features, and gear. Usually, Nintendo announces the release date of upcoming content via their social media accounts. An in-game news announcement introduced the new content when it has been released.

Squid Fashion Contest 2017
In a July 2017 issue, the magazine held the Squid Fashion Contest 2017, which allowed readers to submit gear designs for a chance at having the design added to Splatoon 2. The winning design, a ghillie suit, was added to the game with version. The set includes, , and.

CoroCoro gear
In a November 2017 issue of the CoroCoro magazine announced the release of the "Emperor Gear" set, the set worn by Emperor, the main antagonist of Season 2 of the Splatoon manga. The set includes Eminence Cuff, Milky Eminence Jacket, and Milky Enperrials. To obtain it, players must get a unique download code from the December 2017 issue of CoroCoro magazine. The gear was obtainable on 2017-12-15. The download codes only worked with the Japanese version of Splatoon 2. In November 2018, upon the manga digest release of the Emperor storyline, another run of download codes were distributed.

The original set of codes were valid until July 21, 2019. The digest-insert codes were valid until December 31, 2019.

https://youtu.be/62XYX0aA3wM

Famitsu offered serial code of gear for purchasing the fourth Splatoon Koshien Fan Book. The book was released at 2019-03-04.

7-Eleven & My Nintendo rewards program
Four gear items were were obtainable in Japan through a 7-Eleven promotion, two years later at the final Splatfest: Chaos vs. Order, the western copies were able to obtain the items by purchasing Splatfest Tee shirts that came with code for the in-game gear items, North America & Oceania copies of the game were able to get the code using My Nintendo rewards program by paying 100 Platinum Points. The reward was available until 2020-01-02.