Conthey is a municipality in the district of Conthey in the canton of Valais in Switzerland.
Conthey is first mentioned about 800 as curtis Contextis. In 1146 it was mentioned as ecclesiam de Plano Contesio.
Conthey has an area, , of . Of this area, or 23.3% is used for agricultural purposes, while or 26.3% is forested. Of the rest of the land, or 5.0% is settled (buildings or roads), or 0.9% is either rivers or lakes and or 44.5% is unproductive land.
Of the built up area, housing and buildings made up 2.5% and transportation infrastructure made up 1.5%. Out of the forested land, 21.3% of the total land area is heavily forested and 3.5% is covered with orchards or small clusters of trees. Of the agricultural land, 0.6% is used for growing crops and 1.6% is pastures, while 4.8% is used for orchards or vine crops and 16.4% is used for alpine pastures. Of the water in the municipality, 0.2% is in lakes and 0.6% is in rivers and streams. Of the unproductive areas, 12.7% is unproductive vegetation, 30.5% is too rocky for vegetation and 1.4% of the land is covered by glaciers.
The municipality is located on the right bank of the Rhone in the middle Valais. It stretches from the valley floor to the peak of the Diableret-Massiv. It consists of the village of Conthey (made up of Plan-Conthey, La Place, Le Bourg and Saint-Séverin) and the villages of Aven, Erde, Sensine, Premploz and Daillon in the Derborence area.
The blazon of the municipal coat of arms is Argent, between two Branches of Vine Vert fructed Azure in saltire three Mullets of Five Gules.
Conthey has a population () of . , 18.4% of the population are resident foreign nationals. Over the last 10 years (1999–2009 ) the population has changed at a rate of 18.6%. It has changed at a rate of 18.5% due to migration and at a rate of 1.9% due to births and deaths.
Most of the population () speaks French (5,716 or 91.3%) as their first language, German is the second most common (136 or 2.2%) and Portuguese is the third (130 or 2.1%).