Joensuu ("river's mouth") is a city and municipality in North Karelia, Finland. It was founded in 1848. The population of Joensuu is 76,985 (December 31, 2020), and the economic region of Joensuu has a population of 115,000. The nearest major city, Kuopio in North Savonia, is located 136 kilometres (85 mi) to the west. As is typical of cities in Eastern Finland, Joensuu is monolingually Finnish. Along with Kuopio, Joensuu is one of major urban, economic, and cultural hubs of Eastern Finland.

Joensuu is a lively student city with a subsidiary of the University of Eastern Finland, which has over 15,000 enrolled students, and a further 4,000 students at the Karelia University of Applied Sciences.

The largest employers are the municipal City of Joensuu, North Karelian Hospital District Federation of Municipalities, Abloy and Punamusta.

The European Forest Institute, the University and many other institutes and export enterprises such as Abloy and John Deere give Joensuu an international flavour.