The Acmetropolis Prison is the main prison and jailhouse for all villains and criminals of Acmetropolis. The prison is maintained by the warden. The prison has been known to hold many of the villains that the Loonatics defeat. The prison has the resources to control even the super powered villains that are sent there.
In The Menace of the Mastermind, the prison was shown to hold Mastermind before she escaped to enact revenge on Tech.
In Acmegeddon Part I, Mastermind, Massive, Sypher, and Weather Vane were all sent to the Acmetropolis prison awaiting transport. There they were placed in power neutralizing tubes and were guarded by Duck.
In Cape Duck, the Sagittarius Stomper was sent to jail after being stopped by Tech. Although Tech's invention was what sent the Stomper to prison, the press made it out so Duck was the hero. The Stomper vowed to get back and Duck and the press claimed that no prison has been able to hold him. Despite this, the Stomper's mother, in a bionic suit was sent to prison while the Stomper was free. Showing that he's never actually escaped prison, he just had a double to sit in (and while one of the two was free they probably broke the other out of jail).
- Weather Vane
- Otto the Odd
- Electro J. Fudd
- Sagittarius Stomper
- Ophiuchus Sam (seen in season two intro)