Kotlarnia [kɔˈtlarɲa] is a village in the administrative district of Gmina Bierawa, within Kędzierzyn-Koźle County, Opole Voivodeship, in southern Poland.

In 1702 Jacob Heinrich von Flemming, minister of Polish King Augustus II the Strong, established a brass and wire factory in the village, and later also mirror and spoon factories, which existed until 1848.

[2] During World War II, the Germans operated the E549 forced labour subcamp of the Stalag VIII-B/344 prisoner-of-war camp in the village.

The British prisoners of war shared their food with the starving Jews of Auschwitz.

After Germany's defeat in the war, in 1945, the region became again part of Poland.