Kishin Corps (機神兵団, Kishin Heidan), also called Alien Defender Geo-Armor: Kishin Corps, is a series of Japanese light novels written and illustrated by Masaki Yamada. The series was published in 10 volumes between 1990 and 1994. It is a work of alternate history, taking place in 1941 during World War II. An alien race invades the earth and their forces ally themselves with the Axis powers. To combat these aliens an elite allied unit called the Kishin Corps is created, using alien technology. The story deals with the main character Taishi, who obtains a secret alien device from his father, which the Germans are after to build their own robots.

In 1995, Kishin Corps won the Seiun Award for "Best Japanese Novel of the Year". An original video animation titled Alien Defender Geo-Armor: Kishin Corps was produced by Geneon, co-directed by Takaaki Ishiyama and Kazunori Mizuno, and released in Japan between March 24, 1993, and August 25, 1994.