The thesis discusses the cultural phenomenon of Star Trek and its relationship to religion. It shows the Star Trek's view of religion, what religious elements there are in Star Trek, and it also shows how Star Trek itself can be seen as a religion. The thesis focuses on looking for a unified belief that humans in Star Trek follow, on how humans view religion in extra-terrestrial cultures and what standpoint Starfleet and its members take on this issue. The thesis is divided into two parts: the first one deals with historical-political situation in USA in the time when the various serials were shot, and the second and longer part consists of analyses of various episodes of all the serials and some Star Trek films.