Class M

A Class M planet is a fictional classification of a planet in the science fiction franchise Star Trek. The class denotes a planet that is suitable for supporting humanoid life. They usually have oxygen/nitrogen atmospheres, suitable surface temperatures for humanoid life, earth-like gravity and are water rich. Earth is considered a textbook example of a Class M planet.

Aside from Earth, a few other well known Class M planets in the Star Trek series are: Qo'noS, Cardassia Prime, Vulcan, Romulus and Remus and Bajor.

On the series Enterprise, Sub-commander T'Pol uses the Vulcan term Minshara-Class to mean the same thing.