Utopia Isle is a fictional location created for the Marvel Universe comic series the Squadron Supreme and first appeared in a description by member Power Princess. It appeared in issue Squadron Supreme #1 (1985). The second Utopia Isle also in an alternate universe designated as Earth-31916 appeared in Supreme Power #10-11 also in Marvel Comics.
In the alternate universe of Earth-712 the small island in the southern sea called Utopia Isle stands untouched by outside civilization for countless eons. The people who originally resided on the island calling themselves the Utopians believed themselves to be the result of the alien Kree experimenting on the genetics of Homo sapiens. Due to these genetic enhancements generations to come would become powerful beings, indeed the equivalent of Earth's universe of the Inhumans. The Utopians would develop a culture based upon a peaceful coexisting culture whose people would not have injustice, poverty,crime, illnesses, or sexual discrimination. However the Utopians would stay on Utopia Isle and seclude themselves from all human involvement and therefore develop a sophisticated and peaceful culture in the Island.
As time went on and the outside world modernized and developed nuclear weapons on Earth the Utopians started to worry about the future of not only their way of life but also the worlds. With the use of the Atom bomb they soon decided to leave the planet altogether and designed and created a starship and returned to stars of their fore-bearers to find a new settlement world.
Zarda, also naming herself Power Princess, would stay behind as the Utopians emissary to the Earth. It would be learned later that on Earth-616 at the same location where Utopia Isle was on Earth-712 that the sunken city of Atlantis would be. This indicates that the Utopians were a large civilization, whose counterparts on Earth-616 comprised both the Inhumans and the Atlanteans. The Utopians had used their advanced technology to create an almost indestructible transparent shield. The shield was gifted to Zarda as the chosen ambassador of their culture and to represent as a symbol of Utopians ideals, almost serving as her standard.
It remains unknown what became of the Utopians, but the Squadron Supreme used the ruins on Utopia Isle as their command post and speculated that at some future point they would return to aid their princess in her war against wayward humanity.