Treungen, also known as Tveitsund, is a village located in Telemark county, Norway. It serves as the administrative center for Nissedal Municipality. While Treungen and Tveitsund were originally separate villages, they have grown together over time to form a single large urban area.
The village covers an area of 1.01 square kilometres (250 acres) and had a population of 540 residents in 2022, resulting in a population density of 534 inhabitants per square kilometre. Treungen is notable for being the only population center within Nissedal municipality that exceeds 200 residents.