Leffe (Bergamasque: Léf) is a town and comune near the Alps in Lombardy, Italy. It is located in the Val Gandino, nearly 80 kilometres (50 mi) from Milan, and administratively part of the province of Bergamo. The town is a center of textile industry.

Fossils have been founded during the 20th century in the lignite mines, now preserved at the Museums of Natural Science in Milan and Bergamo. It is mentioned for the first time in a document of 903 with the name of Leufo.