Palazzo Marcello dei Leoni is a palace in Venice, located in the San Polo district and facing the right side of the Grand Canal, between the Rio di San Tomà and Palazzo Dolfin.
Palace owned by the ancient noble Marcello family, it is known by the nickname "dei Leoni" due to the presence of two stone high reliefs set on the sides of the main door, probably coming from the Church of San Tomà after it was rebuilt towards the end of the fourteenth century. Pompeo Gherardo Molmenti lived there, author among other things of various books on Venetian history.
The building has a portico on the ground floor which opens onto the Fondamenta del Traghetto where there are many mooring poles for gondolas. Both on the first and second noble floor there is a three-mullioned window positioned on the right while on the left there is a pair of single-lancet windows, all with round arches while the third floor has four openings without merit, probably the result of a restructuring or elevation of several recent realization.