Juan Eduardo Castro dos Santos (Uruguay, 1954), also known by the nickname of Kensei (??), is an Uruguayan karate grandmaster and Soke ("Founder") of the style Okinawa-ken Ryu.
He was a student, among others, of Georges London, Michihisa Itaya, Sulakshna-Bai, Jintatsu Higa, Seigi Nakamura and Shoshin Nagamine.
He also practices Shodo (Zen calligraphy) and Sumi-e (Zen painting).