Today the municipality of Bieruń is composed of smaller towns such as: Bieruń Stary, Bieruń Nowy, Jajosty, Kopań, Ściernie, Bijasowice, Zabrzeg, Czarnuchowice, and Kopiec which used to be separate in the past. The beginnings of settlement in this region have been lost in the darkness of history. Due to lack of sources, the contemporary science is not able to clearly identify when human activity started here. The documents preserved point out to villages in Ściernie (1272) and Bijasowice (1360). For the first time Bieruń was mentioned in 1376, when it was situated on a trade route between Cracow and Opava. A control and customs point was constructed in the place where the trade route descended the hills towards the marshy area of the Mleczna River. It was a guard tower constructed on a fortified mound. Both the mound and the settlement established around were the origins of the town. The name of the town may come from an old Czech word "berrn" meaning 'duty paid for the ruler'. More precise information regarding the settlement has been provided by a document drawn-up by Ian II of Iron, a duke of Opava and Raciborz (from the Opava Premyslid dynasty), about the passing of the village in Bieruń to a certain Cussowicz. According to this document, a settlement (borgstadel) with a damaged garden, windmill and three ponds existed there before.
The location on important transportation routes facilitated the town's development. However, flourishing development of Bieruń economy took place in mid 16th century when the town was granted market privileges. At that time they traded in: cattle, horses, salt, corn, wool and fish bred in local ponds. Crafts such as smithing, textile work and shoemaking developed considerably. The significance of the office of mound mayor (the representative of land owner) was decreasing gradually, whereas the town council headed by the town mayor became more and more influential.
The spatial layout of the town was typical for all new towns: regular town plan, a nearly square market place surrounded by peoples' houses, with streets branching out from the market place at a right angle. Apart from the church built in 1768 and a few residential houses beside the market square, the town was wooden until the great fire in 1847.
In 1517 Bieruń became a part of the Independent State Country of Pszczyna and its existence was acknowledged by a Czech king Ferdinand I who granted the Free Man title to Hungarian magnates from the Turzo family. In 1525 representatives of this kin presented the town with a brewery and developed fish industry in Bieruń. In 1536 local ponds were expanded, which resulted in the creation of the Great Bieruń Pond, one of the biggest ponds in Silesia at that time. The pond was drained in the 19th century and today a 1.5 km long dike, which was to protect the town from floods, is evidence of the pond's existence.
The Jewish Religious Community was established in the town in mid 18th century. Since 1812 the Community had its synagogue and a cemetery which has been preserved until today.
During the first half of the 19th century, in 1824, the first international road was built in the Upper Silesia. The road led from Wrocław to Cracow passing through Bieruń, among others. A new colony was established in the place where this road crossed the old road from Bytom to Oświęcim, in Zabrzeg (Solec). The colony was named Nowy Bieruń and its development was facilitated thanks to the construction of the Royal-Prussian Main Customs Office, a goods shed, a salt factory, an inn, a primary school as well as a pharmacy, a butcher's shop, a bakery and individual farms. At that time also the Main Post Office operated in Bieruń Nowy. A branch of the District Court authorized to hear criminal offences was established in 1850. The new settlement received its official name 'Nowy Bieruń' in 1833. The establishment of the abovementioned facilities resulted in a large influx of customs officials, border officers, post office clerks, teachers, judges as well as various craftsmen and qualified labourers.
The construction of a new railroad passing Nowy Bieruń and linking the Prussian Silesia with the Austrian Silesia in 1853 facilitated the settlement's growth and contributed to the influx of other professional groups such as railway men. The creation of the second urban cluster gave rise to calling the first cluster 'Stary Bieruń' (Old Bieruń).
The turn of the 19th and the 20th centuries was the period of development and industrialization in the whole Silesia region. At that time the so called 'Siarkownia' match factory was established in Bieruń and a Dynamite Factory was set up in 1871. The water supply system, schools and a number of other social infrastructure elements were built.
A number of enterprises were established in Bieruń in the 1970s, e.g. 'Piast' Coal Mine, 'Śląsk' Diary - now 'Danone' and the Fabryka Samochodów Małolitrażowych FSM ('Small-Engine Car Factory') - now 'Fiat Auto Poland'. At that time Bieruń was not legally independent as it had been incorporated into Tychy in 1975.
After over a dozen years Bieruń regained its independence and became a town on April 2, 1991. However, the town's borders were not preserved, especially in relation to Tychy which retained the manufacturing part of Fiat and the Homer residential district. Thanks to efforts of both Bieruń authorities and the district's residents as well as amendments to tax provisions, the residential district was incorporated into Bieruń eight years later. Certain minor adjustments to the borders with Chełm Śląski were made at that time as well.
Thanks to the regaining of the administrative independence in 1991, Bieruń could develop dynamically. Efforts made by Bieruń and neighbouring municipalities led to the establishment of a country district. The seat of the district office, established in 1998, is also situated in Bieruń. The Centre of Economic Initiatives (CIG), which is the seat of both the Bieruń Foundation of Business Initiatives (BFIG) as well as a number of other entities, was established in Bieruń in 2002. The foundation supports local entrepreneurs' activities. The market square in Bieruń was thoroughly renovated over the years 2004-2005 and consequently in 2005 it was distinguished in the 'Best Space of the Silesian Voivodship' contest. During the market square's renovation a sundial was placed there together with the Silesian Insurgents Monument (located right in the centre and patterned upon the pre-war monument), a historical scale and a well with 'The Drowned' figures - mysterious spirits mentioned in numerous folk tales told in Bieruń.
What is more, thanks to efforts of the Bieruń Municipality, in 2005 the Council of Ministers decided to incorporate over 38 ha of the Bieruń land into the Katowice Special Economic Zone (KSSE). At the cost of PLN 8 million the Bieruń Municipality constructed the crossroads connecting the special zone area with the DK44 road which was repaired in 2007. Furthermore, the District Police Headquarters have operated in the municipality since 2006. 70% of the construction of the police headquarters' seat, which is one of the most modern buildings of this type in Poland, was financed from the municipality's budget. The construction of the social infrastructure building, where departments of the Bieruń town hall are situated, was finished in 2007.