The current estimated population is around 15,300 (as of 2001).
Since 1150, it was known as Mychesk, and renamed under Polish administration to Radomyśl, and after the World War II to the current name.
Radomyshyl was historically a centre of Jewish settlement. In the year 1797 a total of 1,424 people or 80% of the total population were Jewish. In 1847 it had increased to 2,734 and it further increased to 7,502 (67%) in 1897. In 1910 Radomyshl had a Talmud-Torah and five Jewish schools. In 1919 during the Russian Civil War a pogrom by militants under ataman Sokolovsky struck the community. Many were massacred and others fled. In 1921 Radomyshl Synagogue was burned down. By 1926 the Jewish population had declined to 4,637 (36% of the total population). During World War II, Radomyshl was occupied by the German Army from July 9, 1941 to November 10, 1943 then again from December 7 to 26, 1943. During the German invasion the remaining Jews were massacred, and six mass graves have been discovered in the area. Only 250 Jews remained by 1970.