The Metroid is a series of science fiction adventure video games produced by Nintendo. The series was conceived by longtime Nintendo designer Gunpei Yokoi. Metroid combined the platforming of Super Mario Bros. and the exploration aspect of The Legend of Zelda with a decidedly darker atmosphere. The series features one of the first female protagonists in a video game. The series is also noted for nonlinear gameplay. Metroid chronicles the missions of bounty hunter Samus Aran to protect the galaxy from the depradations of the Space Pirates and their attempts to harness the power of fictional organisms such as the Metroid against civilization.

The Metroid series currently consists of ten games across different video game platforms. All of the games in the series have been both critically acclaimed and commercially successful, though each installment has seen varying levels of success. It is also one of Nintendo's best selling franchises with 13 million games sold. Samus Aran has also been featured in many other Nintendo produced games.