Placido Mandanici (3 July 1799, Barcellona Pozzo di Gotto – 6 June 1852, Genoa) was an Italian composer.
He graduated from the Music Lyceum in Palermo (1820), and then studied at Naples with Pietro Raimondi.
He was a friend of Gaetano Donizetti and was a part of the artistic circle centered on Countess Yuliya Samoylova.
To Samoylova he dedicated his opera Il buontempone di Porta Ticinese (1841).
Mandanici spent the last years of his life in Genoa.