Fortuna Antiat, or Fortuna of Antium is a form of the Roman Goddess of fortune or luck worshipped at Antium, the modern Anzio in Italy, located on the western sea-coast. She was worshipped in Antium in a double form, and so properly is called the Fortunae Antiates ("Fortunes of Antium"); They were also known as the Sorores Antii, "the Sisters of Antium". They most likely formed a balanced pair representing the totality of luck which encompasses both good and bad fortune. On a monument of Antium They are called both Fortunae Felici Sacrum ("the Happy and Holy Fortuna") and Forti Fortunae Sacrum ("the Sacred and Mighty Fortuna"). Like the Etruscan Goddess Nortia, an attribute of Fortuna of Antium was the nail, as a symbol of Fate; for by nailing something down its movement is fixed, in the same way that Fate or Fortune is fixed.

The two Fortunas were depicted on a coin of the Emperor Augustus of 18 BCE as two female busts on what is perhaps a cart or altar finished with rams' heads; one, with bared breast, wears a helmet and holds a small offering dish, and Her sister wears a similar crown or helmet and a high-necked tunic. They are described as Fortuna Victrix, "Victorious Fortune" and Fortuna Felix, "Happy Fortune".

Antium was the ancient capital city of the Volscian people, who lived in central Italy, south-east of the Alban Hills. It was a seaside city that in later times was a popular place for the wealthy of Rome to build their villas; but in its early history it was often an enemy of Rome and the Latins. It was said to have been founded by Anthias, a son of the Greek sorceress Kirke; or by Ascanius, a son of Aeneas. Historically, the city of Antium dates from the 5th century BCE, and though some ancient remains have been found, not a trace of the famous temple to Fortuna remains.

Fortuna's worship at Antium included a celebrated oracle, just slightly less famous than the oracle of Fortuna Primigenia at Praeneste. There the paired statues of Fortuna were ritually brought out on a cart, and then were questioned by drawing lots, as at Praeneste; and the statues were said to move or bend forward as they gave their answers. This oracle was quite popular among the people, though never officially consulted by Rome on matters of state; though that didn't stop the Emperor Caligula (of the infamous and blessedly short reign) from consulting it. The oracle told the Emperor to beware of one Cassius; he misinterpreted it and had the wrong one killed, and the correct Cassius later stabbed him to death as he came out of a theatre.

The Oracle of Fortuna in Antium remained in operation even into the time of the Christian Emperor Theodosius in the late 4th century CE.

Also called: Fortuna Antiatina (which also means "Fortuna of Antium")