Yefremov (Russian: Ефре́мов) is a town and the administrative center of Yefremovsky District of Tula Oblast, Russia, located on the Krasivaya Mecha River (Don's tributary), 149 kilometers (93 mi) south of Tula. Population: 42,350 (2010 Census); 47,256 (2002 Census); 56,740 (1989 Census).