Tetsunosuke Onishi (大西 鐡之祐, Ōnishi Tetsunosuke, April 7, 1916 – September 19, 1995) was a professor of Waseda University, coach of the Japan national rugby union team and Waseda University Rugby Football Club. He has been described as a Japanese Carwyn James and was a coach of considerable achievements. He also served as a member of the Japanese Olympic Committee.