Olten (High Alemannic: Oute) is a town in the canton of Solothurn in Switzerland and capital of the district of the same name.

Olten grew into a town during the Middle Ages at the location of a bridge over the Aare.

Its railway station is a major rail hub of Switzerland, located at the junction of lines to Zürich, Basel, Bern, and Lucerne, all of which are within 30 minutes by train, and the town is also home to a depot for Swiss Federal Railways.

Significant amounts of artefacts of the Magdalenian (c. 16'000 to 14'000 years ago) have been excavated near Olten.

At the end of the 3rd century, a fortification was built at the bridge-head, on the south-eastern corner of the earlier vicus.

It is first mentioned in 1201, as Oltun (conjectured as continuing an *Olodunum, with the Gaulish suffix dunum "fort", and a prefix olo-, possibly from a hydronym, thus "river-fort").

Olten passed under the administration of Basel in 1407, which invested in infrastructure, which was however destroyed in fires in 1411 and 1422.

Basel lost interest in rebuilding the town again after the 1422 fire, and sold the settlement to Solothurn in 1426.

Throughout the medieval period, Olten was little more than a fortified bridge-head with some services (blacksmiths, taverns); its total population is estimated to about 500 people for the year 1600.

Olten lost its city rights in 1653 as punishment for its support of the rebels in the Swiss Peasant War.

This resulted in a lasting tradition of resistance against authority in Olten, and the town welcomed as liberators the French troops in the 1798 invasion.

In 1814, Solothurn suppressed another rebellion of Olten patriots against the Swiss Restauration.

More rapid growth set in after the introduction of the railway in 1856, and the town became an industrial and infrastructural center, reaching 7,000 by 1900.

The blazon of the municipal coat of arms is Argent three Fir Trees Vert trunked Gules issuant from a Mount of 3 Coupeaux of the second.

[8] The age distribution, as of 2000[update], in Olten is; 1,011 children or 6.0% of the population are between 0 and 6 years old and 2,083 teenagers or 12.4% are between 7 and 19.

[9] The historical population is given in the following chart:[4][15] The Old City, which includes a Roman era vicus as well as medieval and early modern developments, Train Station, the prehistoric and Roman era hilltop settlement of Dickenbännli, the covered wooden bridge over the Aare and the Naturmuseum are listed as Swiss heritage sites of national significance.

The entire town of Olten is part of the Inventory of Swiss Heritage Sites.

[16] Every year, on 1 August, a large firework show occurs from boats floating down the river.

[17] Located at the crossroads of the most important west–east and north–south lines of Switzerland, Olten has been considered a railway town for more than 150 years.

Swiss Prime Site, one of the most important real estate companies in Switzerland, has its head office in Olten today.

The number of jobs in the primary sector was 14, of which 8 were in agriculture and 6 were in forestry or lumber production.

In the tertiary sector; 1,486 or 14.1% were in wholesale or retail sales or the repair of motor vehicles, 1,882 or 17.8% were in the movement and storage of goods, 577 or 5.5% were in a hotel or restaurant, 977 or 9.3% were in the information industry, 1,204 or 11.4% were the insurance or financial industry, 1,058 or 10.0% were technical professionals or scientists, 785 or 7.4% were in education and 1,356 or 12.8% were in health care.

[9] From the 2000 census[update], 6,803 or 40.6% were Roman Catholic, while 4,262 or 25.4% belonged to the Swiss Reformed Church.

The education system in the Canton of Solothurn allows young children to attend two years of non-obligatory Kindergarten.

The Fachhochschule Nordwestschweiz (polytechnic college of Northwestern Switzerland (applied sciences)) has one of its campuses in Olten.