The heart of Inkopolis is Inkopolis Plaza, where Booyah Base can be found. Stages in Splatoon, such as Urchin Underpass and Blackbelly Skatepark, are located around the city as well. The Inklings you find in the plaza are all players met online through Miiverse. You can see that player's Miiverse posts and order their gear through Spyke. An Inkling's hair color reflects what color they were in their last multiplayer match; it can be any of the well-known colors like Orange, Cyan, Blue, Teal, Magenta, Orange-Yellow, etc. when they leave Turf War. When the Inkling moves on to Ranked Battle, it also has the possibility of more distinguishable colors like Crimson, Minty Green, or Light Yellow. If you've just come out of an online match, inklings you played with may also show up in the plaza as well.
- Booyah Base is a mall in Inkopolis Plaza.
- Inkopolis Plaza is the center of Inkopolis. It is the multiplayer hub and the host of a variety of shops.
- Octo Valley is a large, underground area that serves as the base for the Octarian Army.
- All of Splatoon's stages can be found in Inkopolis.
- Annie is a sea anemone, and the owner of Cooler Heads in Booyah Base.
- Cap'n Cuttlefish is an elderly Inkling who leads the fight against the Octarians.
- Crusty Sean is a shrimp who owns Shrimp Kicks in Booyah Base.
- Jelonzo is a jellyfish who owns Jelly Fresh in Booyah Base.
- Judd is a cat who lives in Inkopolis Plaza and judges multiplayer matches.
- Moe is a small clown fish who lives in Annie's hair.
- Sheldon is a horseshoe crab who owns Ammo Knights in Booyah Base.
- Spyke is a sea urchin who lives in Inkopolis Plaza and aids Inklings with upgrading gear.
- The Squid Sisters, Callie and Marie, are two of Inkopolis' most famous pop stars.
- Inkopolis shares several similarities with Tokyo, Japan, and seems to be based off of this city.
- Inkopolis Tower closely resembles Tokyo Tower.
- The crossing in the plaza resembles Shibuya Crossing.
- The yellow tiles in the plaza are also found in Japan to help the blind. Tiles with different textures may represent such things as an entrance to a shop being nearby.
- The statues on top of the buildings on either side of Inkopolis Tower appear to be of a Kitsune and Tanuki. These are well-known figures in Japanese mythology, and in fact, July 4th's Splatfest theme is "Red Kitsune vs. Green Tanuki" in Japan.
- There is a coffee shop located in between the lobby and Spyke's alley. Although it is always vacant, the Inklings sometimes find it fun to dance outside the shop.
- Opposite the lobby, there is a train station just over the concrete barrier. Although it isn't accessible, a train comes into the station every minute or so.