Neo Zeon is a movement founded and led by Char Aznable with the expressed goal of forcing humanity to migrate into space, by whatever means necessary to further their evolution into Newtypes. They are the main antagonists of the movie Mobile Suit Gundam: Char's Counterattack, with the remnants of the organization serving as the villains of the OVA, Mobile Suit Gundam Unicorn.
In order force humanity to migrate into space, Char decided drop a series of asteroids on Earth, causing a nuclear winter to erupt on the planet and render it uninhabitable. The final asteroid Char planned on dropping was the Axis asteroid, headquarters of Axis Zeon. However, Char's plan was foiled by the Londo Bell taskforce and Amuro Ray. Amuro and Char both lost their lives the end of the conflict.
The remnants of the organization later reorganized into "the Sleeves" and fell under the leadership of Full Frontal, a Cyber Newtype clone of Char Aznable.