| School: | Kage-ryū (陰流) |
| Founder: | Aizu Hyūga-no-Kami Iko (c.1452 - 1538) |
| Date Founded: | c.1490 |
| Period Founded: | Sengoku period (mid-15th century - mid-17th century) |
| Headmaster: | None |
| Headquarters: | None |
| Art1: | Kenjutsu |
| Description1: | Sword art |
| Descendants: | Yagyū Shinkage-ryū • Kashima Shinden Jikishinkage-ryū • Oishi Shinkage-ryū Kenjutsu |
is a traditional school (koryū) of swordsmanship (kenjutsu) founded by Aizu Hyūga-no-Kami Iko (c. 1452 - 1538) in c. 1490. This school is also sometimes called Aizu Kage-ryū after the name of its founder. The founder was also known as Aizu Ikōsai Hisatada, and his surname is sometimes written as "Aisu" instead of "Aizu".
Aizu had two primary students, his son Aizu Koshichiro, and Kamiizumi Hidetsugu --also known as Kamiizumi Ise-no-Kami Nobutsuna -- a famous swordsman and founder of, which would be renamed Yagyū Shinkage-ryū by Nobutsuna's equally famous student Yagyū Sekishūsai Muneyoshi.
Today, the Kage-ryū of Aizu Hyūga-no-Kami Iko exists only through its influence of later schools of swordsmanship, such as Yagyū Shinkage-ryū and Kashima Shinden Jikishinkage-ryū, and the many schools that they in turn influenced.