Klášterec nad Ohří (Czech pronunciation: [ˈklaːʃtɛrɛts ˈnat oɦr̝iː]; German: Klösterle an der Eger) is a town in Chomutov District in the Ústí nad Labem Region of the Czech Republic. It has about 14,000 inhabitants. The town is located on the Ohře River, on the border between the Most Basin, Doupov Mountains and Ore Mountains. Klášterec nad Ohří was known for its porcelain production, but it ended in 2024. The historic town centre is well preserved and is protected as an urban monument zone. The most important monument of the town is the Klášterec nad Ohří Castle.