It takes its name from the Latin word Sedunum, itself derived from the celtic tribe that lived there, the Seduni. It was occupied by the Romans with the rest of the surrounding area in the first century BCE. The town-hall is said to contain several Roman inscriptions, one of which found at Sion memorializes the Roman presence: Civitas Sedunorum Patrono.
The Roman Catholic diocese of Sion is the oldest in Switzerland and one of the oldest north of the Alps.
Sion lost to Turin, Italy in its bid to host the 2006 Winter Olympics. Sion also bid for the 2002 Winter Olympics, which it lost to Salt Lake City, and the 1976 Winter Olympics, which it lost to Denver (the games were re-assigned to Innsbruck when Denver residents voted down additional funding).
The municipal council is the executive power in the commune. Its 15 members, non-permanent except the President, are elected every 4 years by the people.
The commune of Sion comprises also of a counsel of public rights of the medieval commune, the Burgeoisie. Who protect the rights of the original inhabitants against new inhabitants. The counsel is made up of 7 people : a president, a vice-president and five counsellors.
The tertiary sector is the main economic sector in Sion, mainly due to the presence of the cantons administration, the Valaisan parliament and the cantons courthouse. Tourism is also an important sector due to its historic château's and museums.
The secondary sector is also represented.
The primary sector, although marginalised, is ever present. Sion is the third largest wine making region in Switzerland, however, the valuable agricultural land and vineyards are undergoing constant regression due to the process of urbanisation.
Sion has also become an important medical site. The Sion-Region hospital is situated here next to the central institute of Valaisan hospitals and the Romande clinic for physical rehabilitation (SUVA).
Finally the commune hosts a waste incinerator which disposes of the waste from 44 surrounding communes. This incinerator is equipped with a catalytic converter which lowers the levels of NOx emissions below acceptable levels. In addition, the heat created from the combustion is converted into electrical energy which is then provided to local communes.
Sion is host to a number of newspapers, television and radio stations. Such as :
Sion has two high schools (colleges)
Sion is also host to the :
The HES-SO Valais offers education in Sciences, Engineering, Economics, Information Technology and Health Sciences.