Eidos Interactive Ltd. (pronounced /ˈaɪdɒs/, EYE-dos) was a British video game developer and publisher. It is now part of Square Enix Europe.

Its best-known game series include Tomb Raider, Commandos, Deus Ex, Legacy of Kain, Thief, Timesplitters, and Fear Effect. The company maintains offices all around the world, including the United States, Canada, Germany, France, Australia and Japan.

Eidos officially became part of Square Enix on 22 April 2009. Following a reorganization of Square Enix's European operations, Eidos is slated to be consolidated into a new branch, named Square Enix Europe. The Eidos Interactive brand will cease to be used for game publishing thereafter.