Masters of the Universe is a sword and planet-themed media franchise created by Mattel. The main premise revolves around the conflict between He-Man and Skeletor on the planet Eternia, with a vast lineup of supporting characters in a hybrid setting of medieval sword and sorcery, and sci-fi technology. A follow-up series, She-Ra: Princess of Power revolves around He-Man's sister She-Ra and her rebellion against The Horde on the planet Etheria. Since its initial launch, the franchise has spawned a variety of products, including multiple lines of action figures, six animated television series, several comic series, video games, books and magazines, a daily newspaper comic strip, and two feature films.

An action figure is a poseable character model figure made most commonly of plastic, and often based upon characters from a film, comic book, military, video game or television program; fictional or historical. These figures are usually marketed toward boys and adult collectors. The term was coined by Hasbro in 1964 to market G.I. Joe to boys.