San Leonardo al Lago is a Roman Catholic church in the neighborhood of Santa Colomba, within the municipal limits of Monteriggioni, a few kilometers outside of Siena, region of Tuscany, Italy.
The church was originally documented as an Augustinian hermitage in 1119, located near the Lake Verano, now known a Pian del Lago.
The church underwent reconstruction during 13th and 14th centuries, gaining a style transitioning between romanesque and gothic.
The church apse contains frescoes depicting the Life of the Virgin (1360-1370) by Lippo Vanni.
The refectory contains remains of a fresco depicting the Crucifixion (1445) by Giovanni di Paolo del Grazia.