Infinite Stratos, also written as IS <Infinite Stratos> (Japanese: IS〈インフィニット・ストラトス〉, Hepburn: IS <Infinitto Sutoratosu>), is a Japanese light novel series by Izuru Yumizuru with illustrations provided by Okiura (original MF novels) and Choco [ja] (new Overlap novels). As of October 2013, seven volumes have been published by Media Factory under their MF Bunko J label. From volume 8 onwards, the novels were published by Overlap under their Overlap Bunko label.

A manga adaptation by Kenji Akahoshi was serialized in the seinen manga magazine Monthly Comic Alive from May 2010 to July 2012 with five volumes published under their Alive Comics imprint. A 12-episode anime television series adaptation produced by Eight Bit aired in Japan between January and March 2011, and an original video animation (OVA) episode was released on December 7, 2011. The anime is licensed by Sentai Filmworks in North America, who released the series in April 2012. A second series aired from October to December 2013.

In the near future, Japanese scientist Tabane Shinonono creates a high-tech powered exoskeleton called "Infinite Stratos" (IS). Possessing technology and combat capabilities far surpassing that of any other arms system, the IS threatens to destabilize the world. Faced with such an overpowered weapon, the world's nations enact the "Alaska Treaty", stating that ISes shall never be used for military combat purposes, and that the existing IS technology must be equally distributed to all nations, to prevent any one nation from dominating the others. However, sometime after the IS was introduced, society has undergone a drastic change. As ISes can only be operated by women, there is a shift in the power balance between men and women, where women now dominate society over men.

Ten years after the IS was initially introduced, the world has entered a new age of peace. However, a 15-year-old Japanese boy named Ichika Orimura changes everything. During an accidental run-in with a hibernating IS suit, it is revealed that he possesses the innate ability to operate an IS—the only male in the world capable of doing so. Seeing his potential, the Japanese government forcibly enrolls the bewildered young man in the prestigious Infinite Stratos Academy, a multicultural academy where IS pilots from all over the world are trained. Thus, he starts a busy high school life surrounded by girls training to become expert IS pilots. While they seem to be enjoying their thrilling school life, the danger of looming threats and enemies is never too far away.

Infinite Stratos began as a light novel series written by Izuru Yumizuru, with illustrations provided by Okiura. The first volume was published by Media Factory under their MF Bunko J label on May 25, 2009. As of April 25, 2018, twelve volumes have been released.

Due to conflict between the publisher (Media Factory) and the author, publication of the light novels was under suspension. Later, the author confirmed that he is simultaneously writing a new work and continuing Infinite Stratos through Kodansha. The novels are now being published by Overlap under their Overlap Bunko imprint, with Choco [ja] replacing Okiura as illustrator. Reprints of the first seven volumes begun on April 25, 2013, starting with the first two volumes. The series will end in the 13th volume.

The light novels are being translated into traditional Chinese and the first volume was published and released by Sharp Point Press on November 9, 2010. The Chinese translations of the light novels were originally under an indefinite suspension. Yumizuru cited that Media Factory's overseas representatives were engaging in contracts with foreign publishers without the author's permission as the reason for the suspension. Yumizuru had also stated that he was willing to fight over this matter in court if necessary.

On February 27, 2018, J-Novel Club announced it had licensed and begun translating the series into English.