Izyum, city, eastern Ukraine. Izyum is located 75 miles (120 km) southeast of Kharkiv on the Donets River. The earliest historical mention of it dates as early as 1571; it has been a city since 1639. Izyum is linked with Kharkiv and Luhansk by rail. Industries have included railroad repair, brick making, brewing, and optical equipment manufacture. Pop. (2001) 56,114; (2005 est.) 54,593.