Letterboxd, the film-rating platform used by cinephiles worldwide, has published its own ranking of the best science fiction films of all time based on user scores, offering audiences a guide to essential viewing in the genre. The list draws on ratings from Letterboxd's global user base and highlights how certain films, both classic and recent, continue to be held in high esteem by dedicated moviegoers.

Among the entries revealed are Alfonso Cuarón's dystopian thriller Children of Men (2006), rated 4.3/5, which follows Clive Owen's character protecting the first pregnant woman in nearly two decades amid societal collapse. Also featured is the 2025 adaptation of Andy Weir's novel Project Hail Mary, starring Ryan Gosling and also scoring 4.3/5, and John Carpenter's 1982 horror-sci-fi classic The Thing, which achieved a higher 4.4/5 rating.