Unknown Worlds of Science Fiction was a 1970s American black-and-white, science fiction comics magazine published by Marvel Comics' parent company, Magazine Management.

Magazine Management Co., Inc. was an American publishing company lasting from at least c. 1947 to the early 1970s, known for men's-adventure magazines, risqué men's magazines, humor, romance, puzzle, celebrity/film and other types of magazines, and later adding comic books and black-and-white comics magazines to the mix. It was the parent company of Atlas Comics, and its rebranded incarnation, Marvel Comics.