Jirkov is a town located in the Chomutov District of the Ústí nad Labem Region in the Czech Republic. It has a population of approximately 19,000 inhabitants and is situated on the Bílina River at the border between the Ore Mountains and the Most Basin.
The town forms a conurbation with the city of Chomutov. Notable historical monuments within Jirkov include the Church of Saint Giles and the Červený Hrádek Castle.