Koichi Yamauchi (山内 康一, Yamauchi Kōichi, born 1973) is a former Japanese politician of Constitutional Democratic Party of Japan, formerly of the Liberal Democratic Party and Your Party, who served as a member of the House of Representatives in the Diet (national legislature).
A native of Fukuoka Prefecture, he attended Silliman University in Philippines while he was an undergraduate at International Christian University.
He also received a master's degree from the Institute of Education at the University of London.
He was elected to the House of Representatives for the first time in 2005.
This article about a Japanese politician born in the 1970s is a stub.