Kluczbork [ˈklud͡ʐbɔrk] ⓘ (German: Kreuzburg O.S., Silesian: Kluczborek) is a town in southern Poland with 23,554 inhabitants (2019), situated in the Opole Voivodeship.

In Kluczbork the major rail line from Katowice splits into two directions – westwards to Wrocław and northwards to Poznań.

In the late 10th century the Silesian territory was included in the emerging Polish state by its first historic ruler Mieszko I.

In the 13th century the Knights of the Cross with the Red Star acquired territory in Silesia, including the villages of Młodoszów, Kuniów, and Chocianowice.

Named Cruceburg (later spelled Creutzburg, Creuzburg, Kreuzburg), it received Magdeburg rights on 26 February 1253, now accepted as the official date of the town's foundation.

The Knights adjudicated in the town until 1274, when it started to be administered by a vogt of local Silesian dukes and juries were introduced.

The townspeople accepted the Protestant Reformation in 1656 and converted the local Roman Catholic Church into a Lutheran one.

In the 18th century Kreuzburg was annexed by the Kingdom of Prussia in 1741 during the Silesian Wars and became part of the Prussian Province of Silesia.

[4] During World War II, in 1939, the Germans established the Oflag VIII-A prisoner-of-war camp initially for Polish and later for French officers.

In July 1945, the Polish administration issued a decree that all Germans are to wear on their clothing a discriminatory mark with "N" on white background.

[9] Kluczbork's economy is dominated by the production of machinery, knitwear and construction material, alongside newly emerging industries, namely: the transport sector, trade, agriculture and the food production sector as well as being the centre for the Kluczbork County's banks and other financial institutions.

The current investors in the Wałbrzych Special Economic Zone are: Marcegaglia Poland,[10] Inpol-Krak Tubes Service Center and the German Seppeler Gruppe Ocynkownia Śląsk (galvanisation company).