Piacentini is an Italian surname. Notable people with the surname include:
Genison Piacentini de Quadra (born 1988), Brazilian footballer
Giovanni Piacentini (born 1968), Italian footballer
John Piacentini, American psychologist
Marcello Piacentini (1881–1960), Italian architect
Pio Piacentini (1846–1928), Italian architect
Riccardo Piacentini (born 1958), Italian classical composer and pianist
Settimio Piacentini (1859–1921), Italian general