The Republic of Zeon (ジオン共和国 Jion Kyōwakoku?) is a nation featured in the Mobile Suit Zeta Gundam television series and the Mobile Suit Gundam Unicorn OVA. It is the successor state to the Principality of Zeon.
Following the One Year War, the Republic of Zeon was created with a pro-Earth Federation government led by Darcia Bakharov. Although regarded by some as a Federation puppet, the Republic had been granted a degree of autonomy. However, the Federation planned to dissolve the Republic by U.C. 0100, which would cause the name of Zeon and his Newtype theory to fade into obscurity. The Neo Zeon movement, known as "the Sleeves", led by Full Frontal continued to fight for Spacenoid independence. When the Vist Foundation offered them Laplace's Box, an enigmatic object that had the power to topple the Federation government, Frontal intended to use it as a time saver to forestall the dissolution of the Republic so it could help in the formation of the Side Co-Prosperity Sphere, which would boycott the Earth, forcing mass space migration and causing the Federation government to collapse. However, following the defeat of the Sleeves in the Third Neo Zeon War, the Republic of Zeon retired their independence in U.C. 0100 and was folded back into the Earth Federation.