Fondi is a city and comune in the province of Latina, Lazio, central Italy, halfway between Rome and Naples. As of 2017, the city had a population of 39,800. The city has experienced steady population growth since the early 2000s, though this has slowed in recent years. Before the construction of the highway between the latter cities in the late 1950s, Fondi had been an important settlement on the Roman Via Appia, which was the main connection from Rome to much of southern Italy.