The town's name comes from Polish olsza ("Alder"); Olcha is an Old Slavic word for this common plant and tree.

[4] The town is situated in the Silesian Lowlands east of the Trzebnickie Hills, part of the historical region of Lower Silesia.

Located about 30 kilometres (19 mi) northeast of the Silesian capital Wrocław, it has been a stop on an important trade route to the Greater Poland region, Kalisz, Łódź and Warsaw; it had close ties with Kraków via Namysłów in the east.

[6] Oleśnica was located on an important trade route which connected Wrocław with Kalisz and Toruń.

[6] In 1329, Duke Konrad I was forced to accept the overlordship of the Bohemian (Czech) Crown, although he retained vast autonomy.

The written account of this tornado was done by Dr. Alfred Wegener, which is in the CLIMDAT archive located at Leipzig University and the F4 rating on the Fujita scale was assigned by the European Severe Storms Laboratory.

[9] Polish religious writers Adam Gdacius (nicknamed Rey of Silesia) and Jerzy Bock published their works in Oleśnica.

[13] Dozens of Polish resistance members, including women, were held in the local prison, and at least 14 were sentenced to death in the town in 1942.

The town was heavily damaged by the Red Army in 1945 in the final stages of World War II, having approximately 60-80% of its buildings destroyed.

Some 3,000 Italians remained in the town until the end of 1945, and organized artistic shows to which they invited young Polish activists.