- Main article: Inkopolis
Inkopolis is a city in Splatoon and Splatoon 2 inhabited by various races, most notably Inklings, Octolings and Jellyfish. The city consist of many locations were Inklings and Octolings battle in different modes. Within Inkopolis there are two places that serve as hub areas for the player:
For a list of playable arenas, see stages.
- Main article: Octo Valley
Octo Valley is a hidden valley located near Inkopolis, which serves as the setting of the single-player mode of Splatoon with the same name. This valley is the home of the Octarians where they live in domes accessible through kettles.
- Main article: Octo Canyon
Octo Canyon is a hidden canyon located near Inkopolis, which serves as the setting of the single-player mode of Splatoon 2 with the same name. This valley is the home of the Octarians where they live in domes accessible through kettles.
- Main article: Deepsea Metro
- Main article: Salmon Run
There are also some locations that have only been mentioned, but aren't accessible by the player:
- Arowana Castle - Mentioned in the fifth session of Marina's chat room.
- Calamari County - Mentioned as being Callie and Marie's hometown.
- Mount Nantai - Mentioned by the Squid Sisters, Off the Hook and Cap'n Cuttlefish in Splatoon 2. It is stated to be near Octo Valley.
- New Sardine - Mentioned in the twenty-first Sunken Scroll in Splatoon 2. It is stated that this is the location Callie's TV drama is filmed. It is also stated that Callie was spotted on the airport (of Inkopolis) after wrapping up filming, which could mean that New Sardine is quite far away from Inkopolis. The name "New Sardine" is likely a reference to New Orleans in the USA.