The school was established in 1794 by the mathematician Gaspard Monge during the French Revolution, and it was once previously a military academy under Napoleon I in 1804. However, École Polytechnique is no longer a military academy, although the institution is still supervised by the French Ministry of Defence. Initially located in the Quartier Latin of central Paris, the establishment's main buildings were moved in 1976 to Palaiseau on the Plateau de Saclay, southwest of Paris.

Among its alumni are three Nobel prize winners, one Fields Medalist, three Presidents of France and many CEOs of French and international companies. It was ranked 61st internationally by the QS World University Rankings 2021, 93rd by the Times Higher Education World University Rankings 2020, and 2nd by the Times Higher Education Small University Rankings.

Enjoying great prestige in higher education in France, the École Polytechnique is often associated with selectivity and academic excellence, but also with elitism and technocracy which have been sources of criticism since its creation. In the popular imagination, the School is associated with certain symbols such as the student uniform or the Bicorne.