The historic city centre is well preserved and is protected by law as an urban monument zone.

Mladá Boleslav consists of five municipal parts (in brackets population according to the 2021 census):[2] The core municipal parts Mladá Boleslav I–IV are often referred to by their historical names: Staré Město ("Old Town"), Nové Město ("New Town"), Podolec and Pták.

[3] Mladá Boleslav was named after its founder, Duke Boleslaus II, who was called "the Young One", to distinguish him from his father.

In the second half of the 10th century, a gord was founded by Duke Boleslaus II on a promontory, in the area of today's historic centre.

[5] Probably in the 11th century, a settlement was founded below the promontory in an area called Podolec, on an important site on the road from Prague to northern Bohemia, Lusatia and Brandenburg.

Lords of Michalovice died out in 1468 and Mladá Boleslav was acquired by the Tovačovský of Cimburk family.

[5] After death of Adam Krajíř of Krajek in 1588, Mladá Boleslav became property of the Hasištejnský branch of the Lobkowicz family.

During the Thirty Years' War in the first half of the 17th century, the city was twice burned, in 1631 by the imperialists, and in 1640 by the Swedish army.

In 1634, Jacob Bassevi von Treuenberg, the first ennobled Jew in the Habsburg monarchy, was buried in the Jewish cemetery in Mladá Boleslav.

[7] In the 17th and 18th centuries, Mladá Boleslav (called Bumsla by Jews) was an important Jewish centre.

The main factor of its success was its location next to the Jizera River, which was a water source for the newly founded factories.

The most significant was the textile industry – its largest representative, the Česana factory, had more than 2,000 employees at the end of the 19th century.

Another industry in the Jizera valley included mills, breweries, distillery, soaps and perfumes factory, and production of artificial fertilizers.

Most of the factories were gradually shut down during the 20th century, mainly due to World War II and politics of the socialist republic.

[11] In 1895, the Laurin & Klement company (the predecessor of Škoda Auto) was founded and the automotive industry became the main pillar of the city's economy.

[13] The Mladá Boleslav agglomeration was defined as a tool for drawing money from the European Structural and Investment Funds.

The ice hockey team BK Mladá Boleslav has been playing in the top-tier Czech Extraliga without interruption since 2014.

The castle was a ruin after the Thirty Years' War, but at the beginning of the 18th century, it was rebuilt into barracks.

Today it houses the district archive and the Regional Museum with historical, cultural and social history collections.

[20] The Church of Saint John of Nepomuk is located on the eastern edge of the historic city centre and form the dominant feature of Míru Square.

After the Battle of White Mountain, the monastery complex was acquired by the Catholic Church, which rebuilt it in the Baroque style.