San Lazzaro dei Mendicanti is an ancient church in the sestiere of Castello, Venice, northern Italy, with a facade facing a Rio of the same name.

By 1224, a hospital for lepers, dedicated to St Lazarus, patron saint of those afflicted with the disease, was found adjacent to the church of San Trovaso in the sestiere of Dorsoduro.

The term Mendicanti could be derived from two sources: first in 1601, the Mendicant Friars commissioned building of this church from the architect Vincenzo Scamozzi.

For this church, the composer Simon Mayr wrote the oratorios Sisara (based on story of Sisera 1793), Tobiae matrimonium (1794) and David in spelunca Engaddi (1795).

The church contains the ornate funeral monument, completed by Sardi,[1] and dedicated to the condottiero Tommaso Alvise Mocenigo, represented as the admiral who died defending the then-Venetian Candia (Crete) from the Ottomans in 1654, during the Cretan War (1645–1669).