Charles Percier ([ʃaʁl pɛʁsje]; 22 August 1764 – 5 September 1838) was a neoclassical French architect, interior decorator and designer, who worked in a close partnership with Pierre François Léonard Fontaine, originally his friend from student days. For work undertaken from 1794 onward, trying to ascribe conceptions or details to one or other of them is fruitless; it is impossible to disentangle their cooperative efforts in this fashion. Together, Percier and Fontaine were inventors and major proponents of the rich, grand, consciously-archaeological versions of neoclassicism we recognise as Directoire style and Empire style.

Percier was born into a poor Parisian family in 1764. His mother was a laundry woman for Marie-Antoinette and his father was a porter at one of the gates of the Tuileries Palace, who was later promoted into a post in the interior of the palace. This afforded the young Charles Portier an opportunity to observe first hand the lifestyles of the wealthy nobility in a palace that he would, years later, play a major role in rejuvenating.

From the age of 12 onward, Percier attended a free school for teaching drawing, an establishment whose mission was to provide access into the art world for poor students. Percier's talent was quickly recognised. After passing a short time in the studio of a painter named Lagrenée, a place was found for him in the highly respected studio of the renowned architect, Antoine-François Peyre. It was there that he met Pierre Fontaine, with whom he would form a life-long and very successful partnership. Starting in 1794, Fontaine and Percier worked so closely together that it is often difficult to separate their contributions. A 19th century observer noted the following about their intertwined careers: "It is surprising what a complete mastery these young men in a few years contrived to exercise over the tastes of their day."

Percier won the second prix de Rome in 1783, and, in 1784, at the age of twenty years, he won the grand prix de Rome (with a pension). This paid for his stay in Rome. Fontaine had won the second prix de Rome a year earlier and was already in Rome. Percier returned to Paris from Rome in 1791.

One early product of their collaboration was Palais, maisons et autres édifices modernes dessinés à Rome ("A palace, houses and other modern buildings designed in Rome"), which attracted the attention of prospective clients when they returned to Paris. At the end of 1792, near the end of the first phase of the French Revolution, Percier was appointed to supervise the scenery at the Paris Opera, a post at the center of innovative design. Fontaine returned from the security of London and they continued at the Opéra together until 1796. Charles-Louis Bernier [fr] was a third member of their team.

Their initial successes in interior decoration came while serving wealthy, private clients: "The first clients of Percier and Fontaine were the financiers Ouvrard, Chauvelin and Gaudin, who had their recently acquired hotels in the Chaussée d'Antin district fitted out and decorated." It was through these private projects, which impressed the influential artist, David, that they first came to the attention of Joséphine de Beauharnais and Napoleon Bonaparte.

Bonaparte thought highly of their work and gave them responsibility for some of the most prestigious projects of the Consulate and the Empire periods, including the creation of the Rue de Rivoli and the development of the Louvre Palace. He appointed them as his personal architects and never wavered in his decision; they worked on imperial projects throughout Napoleon's time in power. The relationship only dissolved when Napoleon abdicated and was exiled to Elba in 1814. From that time forward, Percier conducted a student atelier, a teaching studio or workshop, and Fontaine became the more public face of the partnership.

They worked for ten years (1802–1812) on the Louvre. The old Louvre Palace had not been a royal residence for generations, so it was free of any taint associated with the detested Bourbons. It stood in the heart of Paris, so that the Emperor could be seen coming and going, unlike Versailles, which had been rendered uninhabitable through destruction and looting. They also pierced the first, western part of the rue de Rivoli, and built its distinctive arcades, and, in the process, built the northern, 'Rivoli' wing of the Louvre, thereby competing the Cour Carrée.^:199