Žernov is a village in Semily District, in the Liberec Region, Czechia. Žernov lies at 339 m above sea level, 0.7 km from the Giant mountains. It has 234 inhabitants (2024). The nearest city is Jablonec nad Nisou, 20 km to the northwest. Among the landmarks around are Trosky Castle (5.2 km), Kost Castle (12.0 km) and Valdštejn Castle (7.3 km). Among the natural features are Zebín (13.6 km) and Postojna (6.4 km).