Manuel Garcia O’Kelly (Mannie)
Manuel is the novel's central character, 'The Moon is Harsh Mistress.' Manuel is depicted as the hero and future superman who is guaranteed to survive any future tribulations. Mannie is also the novel's narrator, aged 32. Mannie is also a freelance computer expert.
Professor Bernardo de la Paz
Professor Bernardo is a rebellious person throughout the novel. Despite being a good lecturer, Bernardo joins other rebels to revolt against conventional and communal norms.
Wyoming Knotts (Wyoh)
Wyoh is a predominant revolutionary figure in the novel, and she makes vital decisions that shape the rebellious group. Unfortunately, Wayoh’s opinions are understated and undervalued by other revolution members simply because she is a woman.
Mike (Mycroft Holmes)
Mike (Adam Selene) is a HOLMES IV supercomputer that is one of the most powerful on Earth or on Luna. The computer was expanded so much that it became self-aware and named himself "Mike" for "Mycroft Holmes", the super-brainy brother of Sherlock Holmes. Mike first alerted his technician Manuel O'Kelly Davis to his existence by issuing a huge overpayment check to a janitor. who worked for "Authority" (the Lunar Authority in charge of the penal colony on the Moon.) When Manny went in to see what was amiss with the computer, he discovered Mike was self-aware. They developed a relationship because Mike was lonely and eventually, Mike did some math proving that the Lunar Authority's draining of water to produce grain shipped away to Earth, would result in famine in the colony. He became the secret leader and brains behind a revolutionary plot to free Luna from being a colony of Earth. Mike used the persona "Adam Selene" for his public image and "Mike" to his closest friends who kept his identity as a self-aware computer secret.
The Chairman
The Chairman is a strong character in charge of the FNIC (Federal Nations Investigation Committee.) The Chairman is not given a specific name because he is the clockwork of the Federation. Similarly, the Chairman is a significant figure because he regulates laws and rules governing the Luna Free State.
Senator Mort the Wart
Mort is depicted as an unfortunate gentleman who offers Loonies the protection they do not need. Loonies strongly believe that they are protected by the regulations and policies of the Lunar Authorities.
Juan Alvarez
Alvarez is the Security Chief of Luna. The Lunar Authority helps Alvarez to execute laws. Unfortunately, Alvarez is lonely and frightened because he polices people who are not interested in being policed.
Stuart Rene Lajoie
Stuart is a tourist visiting the Moon and its environs. Stuart breaks the traditions and customs of Luna when he tries to kiss a local woman.
Hazel Meade
Hazel is a minor character who plays a significant role in helping Mannie and Wyo run away from the rally that endangered their lives.
