San Nazzaro Val Cavargna (Western Lombard: ) is a comune (municipality) in the Province of Como in the Italian region Lombardy, located about north of Milan and about north of Como, on the border with Switzerland. As of 31 December 2004, it had a population of 396 and an area of .
San Nazzaro Val Cavargna borders the following municipalities: Carlazzo, Cavargna, Garzeno, Germasino, San Bartolomeo Val Cavargna, Sant'Antonio (Switzerland), Val Rezzo.