The State Library of Württemberg (German: Württembergische Landesbibliothek or WLB) is a large library in Stuttgart, Germany, which traces its history back to the ducal public library of Württemberg founded in 1765. It holds c. 3.8 million volumes and is thus the fourth-largest library in the state of Baden-Württemberg (after the university libraries of Freiburg, Heidelberg and Tübingen).