Charlie, the princess of Hell and estranged daughter of Lucifer, is pursuing her seemingly impossible goal of rehabilitating demons to peacefully reduce overpopulation in her kingdom.

After a yearly extermination imposed by angels, she opens the Hazbin Hotel to rehabilitate sinners so they can redeem themselves into Heaven. While most of Hell mocks her efforts, her devoted partner Vaggie, and their first test subject, adult-film star Angel Dust, stand by her side.

When a powerful entity known as the Radio Demon reaches out to assist Charlie in her endeavors, her crazy dream is given a chance to become a reality.