Formia is a city and comune in the province of Latina, on the Mediterranean coast of Lazio, Italy. It is located halfway between Rome and Naples, and lies on the Roman-era Appian Way. It has a population of 38,095.

The Appian Way is one of the earliest and strategically most important Roman roads of the ancient republic. It connected Rome to Brindisi, in southeast Italy. Its importance is indicated by its common name, recorded by Statius, of Appia longarum... regina viarum . The road is named after Appius Claudius Caecus, the Roman censor who, during the Samnite Wars, began and completed the first section as a military road to the south in 312 BC.