Francis II (Neapolitan and Italian: Francesco II, Sicilian: Francischieddu; christened Francesco d'Assisi Maria Leopoldo; 16 January 1836 – 27 December 1894) was the last king of the Two Sicilies before the Italian unification, led by Giuseppe Garibaldi and Victor Emmanuel II of Sardinia. After he was deposed, the Kingdom of the Two Sicilies and the Kingdom of Sardinia were merged into the newly formed Kingdom of Italy.

The only son and heir of King Ferdinand II of the Two Sicilies by his first wife, Maria Christina of Savoy, Francis II was the last of the Bourbon kings of Naples, where he was born in 1836. His education had been much neglected and he proved a man of weak character, greatly influenced by his stepmother, Archduchess Maria Theresa of Austria, whom he feared, and also by the priests and the camarilla, the reactionary court set.

On 3 February 1859 in Bari, Francis married Duchess Maria Sophie of Bavaria, of the ducal Bavarian house of Wittelsbach (a younger sister of Empress Elisabeth "Sissi" of Austria). However, their marriage was unhappy. Their only daughter, Maria Cristina Pia, was born ten years after her parents married and lived only three months (24 December 1869 – 28 March 1870).

Francis II took the throne on 22 May 1859, after the death of his father. For the post of prime minister, he at once appointed Carlo Filangieri, who realised the importance of the Franco-Piedmontese victories in Lombardy and advised Francis II to accept the alliance with the Kingdom of Sardinia proposed by Cavour. On 7 June, a part of the Swiss Guard mutinied, and while the king mollified them by promising to redress their grievances, General Alessandro Nunziante gathered his troops, who surrounded the mutineers and shot them down. The incident resulted in the disbanding of the whole Swiss Guard, which was the strongest bulwark of the Bourbon dynasty.

Cavour again proposed an alliance to divide the Papal States between Piedmont and Naples (the province of Rome excepted), but Francis rejected the idea, which to him seemed like heresy. Filangieri strongly advocated a constitution as the only measure which might save the dynasty, but on the king's refusal, he resigned.

Meanwhile, the revolutionary parties were conspiring for the overthrow of the Bourbons in Calabria and Sicily, and Giuseppe Garibaldi was preparing for a raid in the south of Italy. A conspiracy in Sicily was discovered and the plotters punished with brutal severity, but Rosalino Pilo and Francesco Crispi, who had organised the movement, escaped execution. When Garibaldi landed at Marsala (May 1860) with his Expedition of the Thousand, he conquered the island with astonishing ease.

Those events at last coaxed Francis II into granting a constitution, but its promulgation was followed by disorders in Naples and the resignation of several ministers; Liborio Romano became head of the government. The disintegration of the army and navy proceeded apace, and Cavour sent a Piedmontese squadron carrying troops on board to watch over these events. Garibaldi had crossed the strait of Messina and was advancing northward. After long hesitations and even an appeal to Garibaldi himself and on the advice of Romano, Francis II left Naples on 6 September with his wife, Maria Sophie; the court; and the diplomatic corps (except the French and British ministers) and went by sea to Gaeta, where a large part of the army was concentrated.

The next day, Garibaldi entered Naples, was enthusiastically welcomed, and formed a provisional government.