The Roudnice Lobkowicz Library is a large private collection of books kept at Nelahozeves Castle, 35 km north of Prague, Czech Republic. The library belongs to the Lobkowicz family, a noble dynasty of Bohemia. Together with the family's collection of artworks, music, and other valuable assets, the library forms the Lobkowicz Collection, most of which is held in the Lobkowicz Palace, part of the Prague Castle complex. The library comprises about 65,000 volumes – including 679 manuscripts and 730 incunabula. It is the largest castle library in the Czech Republic.