Subtitle 2001: A Space Odyssey -

: Much like Odysseus, Dave Bowman undergoes a perilous voyage far from home, encountering "monsters" (the AI HAL 9000) and ultimately facing a transformation.

The subtitle signals Kubrick's intent to treat science fiction with "mature grandiosity". By avoiding conventional narrative techniques and relying on visual storytelling, Kubrick uses the "Space Odyssey" framing to evoke a sense of awe and existential mystery. The film is widely regarded as a "freestanding work of art" that functions like a living myth, open to interpretation rather than fixed to a specific era.

Ultimately, the subtitle reminds the viewer that the film is not just about a specific year or a specific mission to Jupiter; it is an investigation into "life, death, rebirth, and existentialism". 2001: A Space Odyssey — Explained | by Manny Rothman

The subtitle highlights the tension between the cold precision of the year "2001" and the organic, unpredictable nature of an "Odyssey."