The settlement was first mentioned in a Latin document of Diocese of Wrocław called Liber fundationis episcopatus Vratislaviensis from around 1305 as item in Ustrona. It meant that the village was in the process of location. The creation of the village was a part of a larger settlement campaign taking place in the late 13th century on the territory of what would later be known as Upper Silesia. Politically, the village belonged initially to the Duchy of Teschen, formed in 1290 in the process of feudal fragmentation of Poland, and was ruled by a local branch of Piast dynasty. In 1327, the duchy became a fee of Kingdom of Bohemia, which, after 1526, became part of the Habsburg Monarchy. The village became a seat of a Catholic parish, mentioned in the register of Peter's Pence payment from 1447 among the 50 parishes of Teschen deanery as Wstrowe. In 1772, the Klemens Steel Works was opened and the village was gradually industrialised. When the steel work was closed in 1897 the market town switched to be more orientated towards a health and spa resort. After the Revolutions of 1848 in the Austrian Empire, a modern municipal division was introduced in the re-established Austrian Silesia. Ustroń as a municipality was subscribed to the political district of Bielsko and the legal district of Skoczów. In 1856, it gained market town rights. According to the censuses conducted in 1880, 1890, 1900 and 1910 the population of the municipality dropped from 4375 in 1880 to 4275 in 1910, with a majority being native Polish-speakers, a growing minority speaking German, and dwindling Czech-speaking population. In terms of religion, the majority were Protestants, followed by Roman Catholics and Jews. Ustroń was also traditionally inhabited by Cieszyn Vlachs, speaking Cieszyn Silesian dialect. After World War I, the fall of Austria-Hungary, the Polish–Czechoslovak War and the division of Cieszyn Silesia in 1920, it became a part of Poland. It was then annexed by Nazi Germanyat the beginning of World War II. After the war it was restored to Poland. It gained city rights in 1956. Since the 1960s it saw a large development of new hotels and health centers. A cluster of pyramid-shaped hotels were built in the town. It was also expanded by merger of the surrounding villages: Nierodzim in 1974, Hermanice and Lipowiec in 1975.
