There is evidence that the region of present-day Nice was inhabited as far back as 400,000 years ago, during the Lower Paleolithic age. The archaeological site of Terra Amata near Nice indicates the construction of houses and one of the earliest uses of fire. It is believed that the foundations of the huts discovered here are among the earliest examples of human settlements in the world.

The oldest part of Nice is Cimiez. Romans settled here in the 1st Century BC. By the 3rd Century AD, Cimiez had reached 20,000 inhabitants. It was the capital of a Gaul province, Alpes Maritimae. Traces of Roman civilization can be found in the arenas and thermal baths they built in Cimiez. In addition, the Roman amphitheatre survives to this day.

The city of Nice, or Nicaea as it was initially called, was actually founded by the Greeks. They named it after Nike, the goddess of victory, in honor of their recent triumph over the neighbouring Ligurians. Soon it became a major trade centre on the Ligurian Coast. Its main rival in that regard was the aforementioned Cimiez, which survived as a separate city until the Lombard invasions.

The towns of Liguria entered a league, of which Nice became a member in the 7th Century. In 729, the city withstood the attack of the Saracens. They plundered it during the second half of the 9th Century, however, and retained authority over the surrounding region for much of the 10th Century.