The third chapel on the left-hand side of the nave. The chapel contains several funeral monuments of the Mellini family, and is seriously overcrowded with tombs. The chapel is dedicated to St Nicholas of Tolentino. The first patron of this chapel was Pietro Mellini, a celebrated jurist from the end of the 15th century. In the 1620s Cardinal Giovanni Mellini had the chapel restored and redecorated in Baroque style. The main altar was consecrated in 1628.