Antoninus of Piacenza

For the 6th-century author of a pilgrim's itinerary of the Holy Land, sometimes called Antoninus, see Anonymous pilgrim of Piacenza.

Saint Antoninus of Piacenza (or Placentia) (died 303 AD) is a patron saint of Piacenza in Italy. He is venerated as a saint and martyr in the Roman Catholic Church, with a feast day of 30 September.

The saint was said to have been martyred at Piacenza or Travo, in the 303 AD Diocletianic Persecution. He appears in Victricius' De Laude Sanctorum of the same century, and the somewhat later Martyrologium Hieronymianum. Sabinus of Piacenza established his sanctuary, following a rediscovery of the relics. A later tradition made him a member of the legendary Theban Legion. Piacenza's Basilica di Sant'Antonino bears his name.