Trondheim (UK: TRON(D)-hyme, US: TRON-haym, Urban East Norwegian: [ˈtrɔ̂nː(h)æɪm] (listen); Southern Sami: Tråante), historically Kaupangen, Nidaros and Trondhjem (locally [ˈtrɔ̂nːjæm]), is a city and municipality in Trøndelag county, Norway. It has a population of 205,332 as of 2020, and is the third most populous municipality in Norway, although the fourth largest urban area. Trondheim lies on the south shore of Trondheim Fjord at the mouth of the River Nidelva. Among the major technology-oriented institutions headquartered in Trondheim are the Norwegian University of Science and Technology (NTNU), the Foundation for Scientific and Industrial Research (SINTEF), and St. Olavs University Hospital.
The settlement was founded in 997 as a trading post, and it served as the capital of Norway during the Viking Age until 1217.