Kluczbork (German: Kreuzburg O.S.) is a town in southwestern Poland with 26,670 inhabitants (2003), situated in the Opole Voivodeship. It is the capital of Kluczbork County and an important railroad junction. In Kluczbork the major rail line from Katowice splits into two directions - westwards to Wroclaw and northwards to Poznań. It is also connected with Fosowskie.