Horní Jiřetín (Czech pronunciation: [ˈɦorɲiː jɪr̝ɛciːn]; German: Obergeorgenthal) is a town in Most District in the Ústí nad Labem Region of the Czech Republic. It has about 2,200 inhabitants. The town is located on the Loupnice Stream on the border between the Most Basin and Ore Mountains, in an area known for lignite mining. The main architectural landmark of Horní Jiřetín is the Jezeří Castle, protected as a national cultural monument.