Wakio Mitsui (三井 辨雄 Mitsui Wakio, born November 24, 1942) is a Japanese politician of the Democratic Party of Japan, a member of the House of Representatives in the Diet (national legislature). A native of Sapporo, Hokkaido and graduate of Showa Pharmaceutical University, he was elected to the House of Representatives for the first time in 2000 after an unsuccessful run in 1996.