Mrtník is a village in Plzeň-North District, in the Plzeň Region, Czechia. Mrtník lies at 456 m above sea level. It has 342 inhabitants (2024). The nearest city is Bolevec, 14.3 km to the southeast. Among the landmarks around are Plasy Monastery (7.2 km), Cathedral of St. Bartholomew (17.2 km) and Great Synagogue (17.2 km). Among the natural features are Krkavec (10.6 km) and Chlum (16.7 km).