South Island is a location that appears in Sonic the Hedgehog: The Movie. It refers to the region in the Land of the Sky that is governed by the President. It is made up of many islands suspended in the sky.
South Island, rather than being a singular island, is a region composed of multiple sky-bound landmasses just above the planet's cloud cover which form a sea of clouds around them. Due to their locations, aircrafts are a necessity to travel between most islands.
South Island has for some time been targeted by Dr. Robotnik, a mad scientist seeking to destroy the region and establish himself as Planet Freedom's ruler. However, his plots were always foiled by South Island's defenders, namely Sonic the Hedgehog and Tails.
Sonic the Hedgehog: The Movie
In a scheme to get Sonic's data for his Hyper Metal Sonic, Dr. Robotnik infiltrated South Island's Presidential House and convinced Sonic and Tails to go to Robotropolis by lying that the Robot Generator there would blow up South Island left unchecked. While the heroes was gone, Robotnik kidnapped the President's daughter Sara. Not long after, Hyper Metal Sonic arrived and laid waste to much of South Island before the heroes started to mobilize against him.
- Sonic and Tails' island: The home of Sonic and Tails, this island features a lush jungle environment, a mountain and a large lake. An old junk yard of transport vessels serves as the duo's residence. Crabmeats can be found roaming the island.
- Capital: The capital of South Island is a large city built on a series of islands and is the location of the Presidential House. There are some interconnecting bridges that connect these islands and some of them are developed and have skyscrapers and other modern structures on top of them.
- Green Lake City: Green Lake City is one of the cities in the region. It was reported to be flooded, possibly due to Hyper Metal Sonic.
- Forest Town: Forest Town is one of the cities in the region. It was reported to have been burnt down, possibly by Hyper Metal Sonic.