IS (Infinite Stratos) (IS〈インフィニット・ストラトス〉, IS (Infinitto Sutoratosu)?), often referred to as simply IS, is a Japanese Light novel series by Izuru Yumizuru with illustrations provided by Okiura (Volume 1 - 7) and CHOCO (since Volume 8).

As of August 2013, 8 volumes have been released, The first 7 were published by Media Factory under their MF Bunko J label. Since Volume 8th, the series is published by Overlap under their Overlap Bunko label

A Manga adaptation by Kenji Akahoshi started serialization in the Monthly Comic Alive from May 27, 2010 to July 27, 2012. The second Manga adaption is currently running on Monthly Sunday Gene-X magazine of Shogakukan, illustrated by Yuuki Homura. An Anime adaptation began broadcasting in Japan from January 7 to March 31, 2011. The second season was aired from October 3 to December 9, 2013. Two OVA had been released in December 21, 2011 and October 31, 2013 respectively. The third OVA is scheduled to be released in November 26, 2014.