The third easternmost town in the Czech Republic is situated on the western bank of the Olše River. It is one of the most important and busiest border crossings to Poland.

The town was founded in 1920 by the decision of the Ambassadorial Conference on the division of the territory of Teshinsko between the newly formed Czechoslovakia and Poland. The established border ran through the town of Těšín along the Olše River, dividing it into two parts - Český Těšín and Cieszyn.

In the first period of its independent existence, the town developed as a modern centre of the easternmost tip of the Czech lands, as a town situated eccentrically on the very borders of the state, but benefiting strongly from its correct administrative designation and its position as a railway junction.

In October 1938, after an ultimatum from the Polish government, which took advantage of the weakening of the Czechoslovakia after the Munich Agreement, Český Těšín was occupied by Polish troops and annexed to the Polish Cieszyn as Cieszyn Zachodni - West Těšín. After the defeat of Poland in 1939, it was annexed, along with the Polish part, to Germany. The retreating Polish troops then blew up the bridge over the Olše River.

During World War II, the prison camp Stalag VII D Teschen was located on the territory of Český Těšín. In the initial period, prisoners from France, Yugoslavia, Belgium and Poland were placed in the camp, later also from Great Britain, the Soviet Union and Italy. After the Second World War, the majority German population and some Poles were displaced, and Czechs from the interior began to move into the town instead.

In the following years, the town became known mainly as a centre of the paper and printing industry.

Český Těšín also offers natural attractions. Not every town or region can boast its typical plant or rock. In this case, the flower is the starflower, popularly known as the Těšín's starflower. Its tiny yellow flowers are one of the first flowers to bloom in spring, especially in deciduous forests on fertile, calcareous soils. For many years now, the local authorities of the towns and villages of the Teshin region have been presenting gold and silver stylized starflowers to deserving persons.

Těšínite, originally teschenite, is an igneous rock whose name derives from the town of Těšín. It was given this name by the German geologist and mining engineer Ludwig Hohenegger in 1861.