Varenna is a comune (municipality) on Lake Como in the Province of Lecco in the Italian region Lombardy, located about 60 km north of Milan and about 20 km northwest of Lecco.
Varenna borders the following municipalities: Esino Lario, Lierna, Oliveto Lario, Perledo; and, across the lake in the province of Como: Bellagio, Griante, Menaggio. The main sights is the Castello di Vezio, which, among the rest, houses a small museum dedicated to the Lariosaurus, a sea reptile from the Middle Triassic period.
Varenna was founded by local fishermen in 769, and was later allied of the commune of Milan. In 1126 it was destroyed by the rival commune of Como, and later received the refugees from the Isola Comacina, who had met the same fate (1169).
It is served by a station on the Tirano–Lecco railway.