Cathedral of St. Nicholas, Bielsko-Biała

Mikołaja) is the main Roman Catholic Church of the city of Bielsko-Biała, in the Silesian Voivodship, Poland.

Founded between 1443 and 1447, it was almost completely rebuilt at the beginning of the 20th century according to a design by Viennese architect Leopold Bauer.

Another artist from Vienna, Rudolf Harflinger, designed the stained-glass windows.

The city was in that time part of the Austro-Hungarian Empire, in the crownland Silesia.

In 1992, the church became the cathedral of the newly created dioceses of Bielsko and Żywiec.