From Termini Station you can take bus 64 towards STAZIONE S. PIETRO square and get off at the C.SO VITTORIO EMANUELE / S stop. A. DELLA VALLE.
Buses that stop near Navona square:
46,571, 492, 62, 628, 64 , 70, 81, 87, 916 e C3.
n15, n20, n5, n6 e n7.