Marain is a constructed language used by the Culture, a fictional anarchic, socialistic and utopian society invented by Iain M. Banks and described by him in several of his novels and shorter fictions. Banks's second Culture novel, The Player of Games, is widely considered to be the best introduction to the Culture. The argument that an economy of abundance renders anarchy viable (or even inevitable) attracts many as an interesting potential experiment, were it ever to become testable.

Marain was designed by the Culture's hyperintelligent Minds. In Iain M. Banks' Culture novels, machines (i.e., starships, planets and orbitals) have their own Minds: self-conscious entities originally built by humanoid species but which have outsmarted their creators by several orders of magnitude since then.

The Culture believes (or perhaps has proved) the Sapir-Whorf Hypothesis that language affects society, and Marain was constructed by the Minds to exploit this effect. A related comment is made by the narrator in The Player of Games regarding gender-specific pronouns in English. Marain is also regarded as an aesthetically pleasing language and functionally beautiful by all those who use it.