Niccolò di Bernardo dei Machiavelli ( MAK-ee-ə-VEL-ee, US also MAHK-, Italian: [nikkoˈlɔ mmakjaˈvɛlli]; 3 May 1469 – 21 June 1527), was an Italian diplomat, author, philosopher and historian who lived during the Renaissance. He is best known for his political treatise The Prince (Il Principe), written around 1513 but not published until 1532. He has often been called the father of modern political philosophy and political science.

For many years he served as a senior official in the Florentine Republic with responsibilities in diplomatic and military affairs. He wrote comedies, carnival songs, and poetry. His personal correspondence is also important to historians and scholars of Italian correspondence. He worked as secretary to the Second Chancery of the Republic of Florence from 1498 to 1512, when the Medici were out of power.

After his death Machiavelli's name came to evoke unscrupulous acts of the sort he advised most famously in his work, The Prince. He claimed that his experience and reading of history showed him that politics have always been played with deception, treachery, and crime. He also notably said that a ruler who is establishing a kingdom or a republic, and is criticized for his deeds, including violence, should be excused when the intention and the result are beneficial to him. Machiavelli's Prince has been surrounded by controversy since its release. Some consider it to be a straightforward description of political reality. Others view the Prince as a manual, teaching would-be tyrants how they should seize and maintain power. Even into recent times, some scholars, such as Leo Strauss, have restated the traditional opinion that Machiavelli was a "teacher of evil".

The term Machiavellian often connotes political deceit, deviousness, and realpolitik. Even though Machiavelli has become most famous for his work on principalities, scholars also give attention to the exhortations in his other works of political philosophy. While much less well known than The Prince, the Discourses on Livy (composed c. 1517) has been said to have paved the way of modern republicanism. His works were a major influence on Enlightenment authors who revived interest in classical republicanism, such as Jean-Jacques Rousseau and James Harrington. Machiavelli's political realism has continued to influence generations of academics and politicians, including Hannah Arendt and Otto von Bismarck.