The Menton area has been inhabited since the paleolithic era, and is the site of the original "Grimaldi Man" find of early modern humans, as well as remains of Neanderthals and
Cro-Magnons. In Roman times, the Via Julia Augusta, a road connecting Placentia (now Piacenza) with Arelates (now Arles) passed through Menton, running along the Rue Longue in the old town. The first major settlement occurred during the 11th century CE, when the Count of Ventimiglia constructed the Château de Puypin (Podium Pinum) on the Pépin hill, north and west of the modern town center. During the 13th century, the seigneury of Puypin fell to the Vento family of Genoa who built a new castle along the Roman road, now the site of the Vieux-Château cemetery, providing the core around which the current town grew. Menton was thus incorporated into the Republic of Genoa. The first mention of Menton dates from 21 July 1262, in the peace treaty between Charles of Anjou and Genoa. Its position on the border between the Angevin-ruled Provence and the Republic of Genoa, which at the time claimed Monaco as its western limit acquired in 1346 by Charles Grimaldi, Lord of Monaco, Menton was ruled by the Princes of Monaco until the French Revolution. Annexed during the Revolution, Menton remained part of France through the First Empire. It belonged to the district of Sanremo in the department of Alpes-Maritimes, which at the time included Monaco and Sanremo. In 1814 Menton was included in a reconstituted principality of Monaco which, after Napoleon's Hundred Days in 1815, became a protectorate of the King of Sardinia. The Princes of Monaco were obliged to do homage to the King for Menton, although not for Monaco itself.
The Treaty of Turin concluded on 24 March 1860 between the Kingdom of Sardinia and Napoleon III's France called for the annexation of the County of Nice to France, subject to a plebiscite, as a reward for French assistance in Italy's war against Austria. The plebiscite, with universal adult male suffrage, was held on April 15 and 16, 1860 and resulted in an overwhelming vote in favor of annexation (833 for versus 54 against in Menton and Roquebrune), despite complaints of rigged elections from, among others, Nice-born Italian nationalist Giuseppe Garibaldi. . The county of Nice was thus annexed to France that June, and Napoleon III paid 4 million francs in compensation to the prince of Monaco, who renounced his rights in perpetuity on 2 February 1861.
From the end of the 19th century, tourism became an important factor in Menton. The town was popular with English and Russian aristocrats who built many of the luxurious hotels, villas, and palaces which still grace Menton today. Many of these hotels and palaces were pressed into service as hospitals during World War I to allow injured troops to recuperate in a pleasant climate.
Menton was the only sizable settlement captured by Italy during its invasion of France in June 1940. Following the armistice of June 22, 1940, two-thirds of the territory of the commune was annexed by Italy as terra irredenta. The annexation lasted until 8 September 1943.
Although officially returned to Vichy France, Menton was in fact occupied by Nazi Germany until its liberation by American and Canadian troops of the First Special Service Force on 8 September 1944.
