Italian irredentism in Nice was the political movement supporting the annexation of the County of Nice to the Kingdom of Italy. The term was coined by Italian Irredentists.
According to some Italian nationalists and fascists like Ermanno Amicucci, Italian- and Ligurian-speaking populations of the County of Nice (Italian: Nizza) formed the majority of the county's population until the mid-19th century. However, modern linguistics refutes this theory: Occitan and Ligurian languages were spoken in the County of Nice.
During the Italian unification, in 1860, the House of Savoy allowed the Second French Empire to annex Nice from the Kingdom of Sardinia in exchange for French support of its quest to unify Italy. Consequently, the Niçois were excluded from the Italian unification movement and the region has since become primarily French-speaking.
The region around Nicaea, as Nice was known in Latin, was inhabited by the Ligures until its occupation by the Roman Empire. The Ligures were conquered by Augustus and, according to Theodor Mommsen, fully romanised by the 4th century, when the invasions of the Migration Period began.
The Franks conquered the region after the fall of Rome, and the local Romance language speaking populations became integrated within the County of Provence, with a period of independence as a maritime republic (1108–1176). In 1388, the commune of Nice sought the protection of the Duchy of Savoy, and Nice continued to be controlled, directly or indirectly, by the Savoy monarchs right up until 1860.