The March on Rome (Italian: Marcia su Roma) was an organized mass demonstration in October 1922 which resulted in Benito Mussolini's National Fascist Party (Partito Nazionale Fascista, PNF) ascending to power in the Kingdom of Italy.

In late October 1922, Fascist Party leaders planned a march on the capital. On 28 October, the fascist demonstrators and Blackshirt paramilitaries approached Rome; Prime Minister Luigi Facta wished to declare a state of siege, but this was overruled by King Victor Emmanuel III, who, fearing bloodshed, persuaded Facta to resign by threatening to abdicate. On 30 October 1922, the King appointed Mussolini as Prime Minister, thereby transferring political power to the fascists without armed conflict. On 31 October the fascist Blackshirts paraded in Rome, while Mussolini formed his coalition government.

In March 1919, Benito Mussolini founded the first Italian Fasces of Combat (FIC) at the beginning of the so-called Red Biennium, a two-year long social conflict between the Italian Socialist Party (PSI) and the liberal and conservative ruling class. Mussolini's Fascists suffered a defeat in the election of November 1919, winning no seats in the Italian parliament.^{[further explanation needed]}

During the "two red years", there were numerous strikes, protests against rises in the cost of living, occupations of factories and land by industrial workers or agricultural laborers, and other types of clashes between socialists on one side and landowners and business owners on the other side. The government tried to play the role of neutral mediator, which dissatisfied both sides. Local elites felt themselves vulnerable and established an alliance with the small Fascist movement, which contained many veterans of World War I and had a reputation for violence, in the hope of using Fascist paramilitary squads to destroy socialist organizations.

In September 1919, Gabriele D'Annunzio and his armed followers took over the Adriatic town of Fiume, seeking to secure its transfer from Kingdom of Serbs, Croats and Slovenes to Italy. D'Annunzio and his followers controlled the city until their expulsion in December 1920. The occupation of Fiume served as a partial "precedent and inspiration" for the March on Rome.

Since 1919, Fascist militias, known as squadristi or "Blackshirts" due to their uniforms, had frequently attacked socialist politicians and militants. In August 1920, the Blackshirt militia was used to break the general strike which originated at the Alfa Romeo factory in Milan, while in November 1920, after the assassination of Giulio Giordani (a right-wing municipal councillor in Bologna), the Blackshirts were active in the suppression of the socialist movement, which included a strong anarcho-syndicalist component, especially in the Po Valley.

Local elections in 1920 were won by the socialists in many towns, cities and villages across Italy, and in response Fascist militias attacked union organizers and municipal administrators, making it difficult for local governments to function. A local deputy from the town of Budrio sent a telegram to the prime minister in October 1921 to report that the Fascists had effectively taken over, that "unions and socialist clubs [were] ordered to dissolve themselves within 48 hours or face physical destruction" and that the "life of the town is paralysed, authorities impotent". Similar situations also occurred in other towns across Northern and Central Italy from 1920 to 1922. The police repeatedly failed to intervene against Fascist violence, and in some cases police officers openly supported the Fascists and supplied them with weapons.

In the 1921 general election the Fascists ran within the National Blocs of Giovanni Giolitti, an anti-socialist coalition of liberals, conservatives and fascists. The Fascists won 35 seats and Mussolini was elected in the Parliament for the first time.