The House of Bonaparte (originally Buonaparte) is a former imperial and royal European dynasty of French and Italian origin. It was founded in 1804 by Napoleon I, the son of Corsican nobleman Carlo Buonaparte and Letizia Buonaparte (née Ramolino). Napoleon was a French military leader who rose to power during the French Revolution and who, in 1804, transformed the French First Republic into the First French Empire, five years after his coup d'état of November 1799 (18 Brumaire). Napoleon and the Grande Armée had to fight against every major European power (except for the ones he was allied with, including Denmark-Norway) and dominated continental Europe through a series of military victories during the Napoleonic Wars. He installed members of his family on the thrones of client states, expanding the power of the dynasty.

The House of Bonaparte formed the Imperial House of France during the French Empire, together with some non-Bonaparte family members. In addition to holding the title of Emperor of the French, the Bonaparte dynasty held various other titles and territories during the Napoleonic Wars, including the Kingdom of Italy, the Kingdom of the Spain and the Indies, the Kingdom of Westphalia, the Kingdom of Holland, and the Kingdom of Naples. The dynasty held power for around a decade until the Napoleonic Wars began to take their toll. Making very powerful enemies, such as Austria, Britain, Russia, and Prussia, as well as royalist (particularly Bourbon) restorational movements in France, Spain, the Two Sicilies, and Sardinia, the dynasty eventually collapsed due to the final defeat of Napoleon I at the Battle of Waterloo and the restoration of the Bourbon dynasty by the Congress of Vienna.

During the reign of Napoleon I, the Imperial Family consisted of the Emperor's immediate relations – his wife, son, siblings, and some other close relatives, namely his brother-in-law Joachim Murat, his uncle Joseph Fesch, and his stepson Eugène de Beauharnais.

Between 1852 and 1870, there was a Second French Empire, when a member of the Bonaparte dynasty again ruled France: Napoleon III, the youngest son of Louis Bonaparte. However, during the Franco-Prussian War of 1870–1871, the dynasty was again ousted from the Imperial Throne. Since that time, there has been a series of pretenders. Supporters of the Bonaparte family's claim to the throne of France are known as Bonapartists. Current head Jean-Christophe, Prince Napoléon has a Bourbon mother.

The Bonaparte (originally Italian: Buonaparte) family were patricians in the Italian towns of Sarzana, San Miniato, and Florence. The name derives from Italian: buona ("good") and parte ("part" or "side"). In Italian, the phrase "buona parte" is used to identify a fraction of considerable, but undefined, size in a totum.

Gianfaldo Buonaparte was the first known Buonaparte at Sarzana around 1200. His descendant Giovanni Buonaparte in 1397 married Isabella Calandrini, a cousin of later cardinal Filippo Calandrini. Giovanni became mayor of Sarzana and was named commissioner of the Lunigiana by Giovanni Maria Visconti in 1408. His daughter, Agnella Berni, was the great-grandmother of Italian poet Francesco Berni and their great-grandson Francesco Buonaparte was an equestrian mercenary at the service of the Genoese Bank of Saint George. In 1490, Francesco Buonaparte went to the island of Corsica, which was controlled by the bank. In 1493, he married the daughter of Guido da Castelletto, representative of the Bank of Saint George in Ajaccio, Corsica. Most of their descendants during subsequent generations were members of the Ajaccio town council. Napoleon's father, Carlo Buonaparte, received a patent of nobility from the King of France in 1771.

There also existed a Buonaparte family in Florence; however, its possible relationship with the Sarzana and San Miniato families is unknown. Jacopo Buonaparte of San Miniato was a friend and advisor to Medici Pope Clement VII. Jacopo was also a witness to and wrote an account of the sack of Rome, which is one of the most important historical documents recounting that event. Two of Jacopo's nephews, Pier Antonio Buonaparte and Giovanni Buonaparte, however, took part in the 1527 Medici rebellion, after which they were banished from Florence and later were restored by Alessandro de' Medici, Duke of Florence. Jacopo's brother Benedetto Buonaparte maintained political neutrality. The San Miniato branch extinguished with Jacopo in 1550. The last member of the Florence family was a canon named Gregorio Bonaparte, who died in 1803, leaving Napoleon as heir.

A Buonaparte tomb lies in the Church of San Francesco in San Miniato. A second tomb, the Chapelle Impériale, was built by Napoleon III in Ajaccio 1857.