The Legion of Super-Heroes and Science Police defend this interstellar nation.
The governing body, called the United Planets Inner Council, appears to have five members: the President of Earth and the heads of government of four other planets. One of those members serves as the president of the United Planets.
The capital of the United Planets is Superman's hometown of Metropolis, on the North American continent on Earth. The population of the United Planets is about 300 billion. Later, much of the government and bureaucracy of the United Planets moved to Weber's World, an artificial world constructed for this purpose
The United Planets' enemies include alien races such as the Khunds and the Dominators and organizations such as the Dark Circle, the White Triangle and the Controllers.