Sumy was founded in 1652 at the bank of the Psel River (a left tributary of the Dnieper) as a Cossack fortress. It was intended to protect Sloboda Ukraine from the Crimean Tatar attacks. After their attacks discontinued and the territory was incorporated into the Russian Empire, Sumy evolved into an important economical centre. During the German occupation of Ukraine during World War II (1941 – 1943), Sumy sustained heavy damage. The war over, destroyed parts of the city were rebuilt anew. Sumy has been a twin town of Celle, Germany since January 17, 1990.

The city used to be divided into two city raions (districts): Zarichny and Kovpak. However, they were liquidated in 2006.

A teacher-training institute is located in Sumy. Famous Russian writers A.P.Chekhov and A.I.Kuprin lived in Sumy city. Sumy was visited by composer P.I.Chaikovsky, writer V.G.Korolenko, poet A.N.Pletsheyev.

Among survivals of Sumy city past are the Cathedral of the Transfiguration (1776-1788) and the Church of Resurrection (1702).