The bishop’s settlement – Ustroń – was founded in 1305. At this time, it was a village owned by the Wrocław bishops.The development of Ustroń was enhanced by a favorable location of the trade route from Wieliczka to Slovakia and Hungary. Ustroń suffered the same political fate as the whole Silesia and it was under the Czech rule. In the Counter-Reformation period (16th – 17th centuries) the population of Evangelic faith had to seek refuge in the mountains. In 1621, the army of the Catholic Coalition burned Ustroń. In 1653 Ustroń went under the Habsburgs rule. Iron ore deposits were discovered here in the second half of the 18th century. In 1772 a blacksmith’s, a foundry and a casting house were founded in Ustroń. In 1783, an Evangelic, and later, a Catholic school were opened. In 1804, the town started to develop as a health resort, which made use of the healing properties of water rich in sulfur compounds. In 1893, two villages called Dolny and Górny Ustroń were united into one bigger settlement. In 1897, the foundry furnace was extinguished so that the health resort could freely develop.
During World War II, in September 1939 Ustroń was occupied by the German army.
In 1956 Ustroń was granted a charter.