Ryoichi Takahashi (高橋 良一, Takahashi Ryōichi) (April 6, 1898—July 17, 1963) was a Japanese entomologist. His research focused on hemiptera, including aphids, whiteflies, and scale insects. He published more than 420 articles. Taxa named after him include: * Kondo, 2005 * Kondo, 2005 * Martin & Lau, 2011 * Skvarla et al., 2020 * Kuwana, 1932 * Alexander, 1920 * Esaki, 1923 * Alexander, 1919 * David & Subramaniam, 1976 * Ossiannilsson, 1966 * Boselli, 1930 * Singh, 1933 * (Yosii, 1940) * Danzig, 1966 * David & Jesudasan, 1989 * Kuwayama, 1931