Hideo Watanabe (渡辺 秀央 Watanabe Hideo, born July 5, 1934) is a Japanese politician of the Democratic Party of Japan, a member of the House of Councillors in the Diet (national legislature). A native of Tochio, Niigata and graduate of Takushoku University, he was elected to the House of Councillors for the first time in 1998 after serving in the House of Representatives for six terms.