Charles-Édouard Jeanneret (6 October 1887 – 27 August 1965), known as Le Corbusier, was a Swiss-French architectural designer, painter, urban planner and writer, who was one of the pioneers of what is now regarded as modern architecture. He was born in Switzerland to French-speaking Swiss parents, and acquired French nationality by naturalization in 1930. His career spanned five decades, in which he designed buildings in Europe, Japan, India, as well as North and South America. He considered that "the roots of modern architecture are to be found in Viollet-le-Duc."

Dedicated to providing better living conditions for the residents of crowded cities, Le Corbusier was influential in urban planning, and was a founding member of the Congrès International d'Architecture Moderne (CIAM). Le Corbusier prepared the master plan for the city of Chandigarh in India, and contributed specific designs for several buildings there, especially the government buildings. In 2016, seventeen projects by Le Corbusier in seven countries were inscribed in the list of UNESCO World Heritage Sites as The Architectural Work of Le Corbusier, an Outstanding Contribution to the Modern Movement.

Le Corbusier remains a controversial figure. Some of his urban planning ideas have been criticized for their indifference to pre-existing cultural sites, societal expression and equality, and his alleged ties with fascism, antisemitism, eugenics, and the dictator Benito Mussolini have resulted in some continuing contention. Le Corbusier also designed well-known furniture such as the LC4 chaise longue and the LC1 chair, both made of leather with metal framing.

Charles-Édouard Jeanneret was born on 6 October 1887 in La Chaux-de-Fonds, a city in the Neuchâtel canton in the Romandie region of Switzerland. His ancestors included Belgians with the surname Lecorbésier, which inspired the pseudonym Le Corbusier which he would adopt as an adult. His father was an artisan who enameled boxes and watches, and his mother taught piano. His elder brother Albert was an amateur violinist. He attended a kindergarten that used Fröbelian methods.

Located in the Jura Mountains 5 kilometres (3.1 mi) across the border from France, La Chaux-de-Fonds was a burgeoning city at the heart of the Watch Valley. Its culture was influenced by the Loge L'Amitié, a Masonic lodge upholding moral, social, and philosophical ideas symbolized by the right angle (rectitude) and the compass (exactitude). Le Corbusier would later describe these as "my guide, my choice" and as "time-honored ideas, ingrained and deep-rooted in the intellect, like entries from a catechism."

Like his contemporaries Frank Lloyd Wright and Mies van der Rohe, Le Corbusier lacked formal training as an architect. He was attracted to the visual arts; at the age of fifteen, he entered the municipal art school in La-Chaux-de-Fonds which taught the applied arts connected with watchmaking. Three years later he attended the higher course of decoration, founded by the painter Charles L'Eplattenier, who had studied in Budapest and Paris. Le Corbusier wrote later that L'Eplattenier had made him "a man of the woods" and taught him about painting from nature. His father frequently took him into the mountains around the town. He wrote later, "we were constantly on mountaintops; we grew accustomed to a vast horizon." He reported later that it was L'Eplattenier who made him choose architecture. "I had a horror of architecture and architects," he wrote. "...I was sixteen, I accepted the verdict and I obeyed. I moved into architecture." His architecture teacher was architect René Chapallaz, who had a large influence on Le Corbusier's earliest house designs.

Le Corbusier began teaching himself by going to the library to read about architecture and philosophy, visiting museums, sketching buildings, and constructing them. In 1905, he and two other students, under the supervision of their teacher, René Chapallaz, designed and built his first house, the Villa Fallet, for the engraver Louis Fallet, a friend of his teacher Charles L'Eplattenier. Located on the forested hillside near Chaux-de-Fonds, it was a large chalet with a steep roof in the local alpine style and carefully crafted colored geometric patterns on the façade. The success of this house led to his construction of two similar houses, the Villas Jacquemet and Stotzer, in the same area.

In September 1907, he made his first trip outside of Switzerland, going to Italy; he then spent the winter traveling through Budapest to Vienna, where he stayed for four months and met Gustav Klimt and tried, without success, to meet Josef Hoffmann. In Florence, he visited the Florence Charterhouse in Galluzzo, which made a lifelong impression on him. "I would have liked to live in one of what they called their cells," he wrote later. "It was the solution for a unique kind of worker's housing, or rather for a terrestrial paradise." He travelled to Paris, and for 14 months between 1908 and 1910 he worked as a draftsman in the office of the architect Auguste Perret, the pioneer of the use of reinforced concrete in residential construction and the architectural designer of the Art Deco landmark Théâtre des Champs-Élysées. Two years later, between October 1910 and March 1911 he traveled to Germany and worked for four months in the office of Peter Behrens, where Mies van der Rohe and Walter Gropius were also working and learning.