Taking place in the future of the DC Universe as part of The New 52, the series features a 31st century iteration of the Justice League, with new versions of Superman, Batman, Wonder Woman, the Flash, and Green Lantern.

[2] In the 31st century, humanity has spread its influence across the stars and in an age where heroes are in dire need, the Justice League is reformed for peacekeeping across space.

Using advanced bio-engineering, the duo enabled the creation and survival of duplicates of the five superheroes, but with only fragments of their memories, experiences, heroic mentalities and powers.

In desperation to contain a growing intergalactic threat, Cadmus presses on with their Justice League 3000 experiment with the objective of restoring interstellar order.

[6] Despite Justice League 3000 launching the month following the cancellation of Legion of Super-Heroes, as well as taking place within the same time period, writer Keith Giffen has confirmed that Justice League 3000 is not directly "tied together" with Legion of Super Heroes because "it would be unfair to put out a book that insists you're familiar with another book".