The Japan High School Baseball Federation (財団法人日本高等学校野球連盟 zaidan hōjin nihon kōtō gakkō yakyū renmei) is the governing body of high school baseball in Japan, and is composed of the High School Baseball Federations of each of the 47 prefectures. Together with the All Japan University Baseball Federation (財団法人全日本大学野球連盟 zaidan hōjin zen-nihon daigaku yakyū renmei), it makes up the Japan Student Baseball Association (日本学生野球協会 nihon gakusei yakyū kyōkai). The name is often abbreviated to "Nihon Kōyaren" (日本高野連) or just "Kōyaren" (高野連).
The Kōyaren evolved from the All-Japan Secondary School Baseball Federation (全日本中等学校野球連盟 zen-nihon chutōgakkō yakyu renmei), which was formed in 1946 to oversee the National Secondary School Baseball Championship organized by Osaka Asahi Shimbun before the war.
Due to the outcome of World War II, in 1947 the school system was overhauled, and "secondary schools" became "high schools". Thus the federation was renamed to the All-Japan High School Baseball Federation.
In 1963, the federation became a private foundation separate from the Ministry of Education.