Henri Matisse (French pronunciation (31 December 1869 – 3 November 1954) was a French artist, known for his use of colour and his fluid and original draughtsmanship. He was a draughtsman, printmaker, and sculptor, but is known primarily as a painter. Matisse is commonly regarded, along with Picasso and Marcel Duchamp, as one of the three artists who helped to define the revolutionary developments in the plastic arts in the opening decades of the 20th century, responsible for significant developments in painting and sculpture. Although he was initially labelled a Fauve (wild beast), by the 1920s he was increasingly hailed as an upholder of the classical tradition in French painting. His mastery of the expressive language of colour and drawing, displayed in a body of work spanning over a half-century, won him recognition as a leading figure in modern art.

He first started to paint in 1889, after his mother brought him art supplies during a period of convalescence following an attack of appendicitis. He discovered "a kind of paradise" as he later described it, and decided to become an artist, deeply disappointing his father. In 1891, he returned to Paris to study art at the Académie Julian and became a student of William-Adolphe Bouguereau and Gustave Moreau. Initially he painted still-lifes and landscapes in a traditional style, at which he achieved reasonable proficiency. Matisse was influenced by the works of earlier masters such as Jean-Baptiste-Siméon Chardin, Nicolas Poussin, and Antoine Watteau, as well as by modern artists such as Édouard Manet, and by Japanese art. Chardin was one of Matisse's most admired painters; as an art student he made copies of four Chardin paintings in the Louvre. In 1896 and 1897, Matisse visited the painter John Peter Russell on the island Belle Île off the coast of Brittany. Russell introduced him to Impressionism and to the work of van Gogh, who had been a friend of Russell but was completely unknown at the time. Matisse's style changed completely, and he would later say "Russell was my teacher, and Russell explained colour theory to me. In 1896 Matisse exhibited five paintings in the salon of the Société Nationale des Beaux-Arts, two of which were purchased by the state. In 1898, on the advice of Camille Pissarro, he went to London to study the paintings of J. M. W. Turner and then went on a trip to Corsica. Upon his return to Paris in February 1899, he worked beside Albert Marquet and met André Derain, Jean Puy, and Jules Flandrin. Matisse immersed himself in the work of others and went into debt from buying work from painters he admired. The work he hung and displayed in his home included a plaster bust by Rodin, a painting by Gauguin, a drawing by van Gogh, and Cézanne’s Three Bathers. In Cézanne's sense of pictorial structure and colour, Matisse found his main inspiration.

In 1905, Matisse and a group of artists now known as "Fauves" exhibited together in a room at the Salon d'Automne. The paintings expressed emotion with wild, often dissonant colours, without regard for the subject's natural colours. Matisse showed Open Window and Woman with the Hat at the Salon. Critic Louis Vauxcelles described the work with the phrase "Donatello au milieu des fauves!" (Donatello among the wild beasts), referring to a Renaissance-type sculpture that shared the room with them. His comment was printed on 17 October 1905 in Gil Blas, a daily newspaper, and passed into popular usage. The exhibition garnered harsh criticism—"A pot of paint has been flung in the face of the public", said the critic Camille Mauclair - but also some favourable attention. When the painting that was singled out for special condemnation, Matisse's Woman with a Hat, was bought by Gertrude and Leo Stein, the embattled artist's morale improved considerably. Matisse was recognized as a leader of the Fauves, along with André Derain; the two were friendly rivals, each with his own followers. Other members were Georges Braque, Raoul Dufy and Maurice de Vlaminck. The Symbolist painter Gustave Moreau (1826–1898) was the movement's inspirational teacher; as a professor at the École des Beaux-Arts in Paris, he pushed his students to think outside of the lines of formality and to follow their visions.

Around 1904 he met Pablo Picasso, who was 12 years younger than Matisse. The two became life-long friends as well as rivals and are often compared; one key difference between them is that Matisse drew and painted from nature, while Picasso was much more inclined to work from imagination. The subjects painted most frequently by both artists were women and still life, with Matisse more likely to place his figures in fully realized interiors. Matisse and Picasso were first brought together at the Paris salon of Gertrude Stein and her companion Alice B. Toklas.

In 1917 Matisse relocated to Cimiez on the French Riviera, a suburb of the city of Nice. His work of the decade or so following this relocation shows a relaxation and a softening of his approach. This "return to order" is characteristic of much art of the post-World War I period, and can be compared with the neoclassicism of Picasso and Stravinsky, and the return to traditionalism of Derain. His orientalist odalisque paintings are characteristic of the period; while this work was popular, some contemporary critics found it shallow and decorative. In the late 1920s Matisse notably once again engaged in active collaborations with other artists. He worked with not only Frenchmen, Dutch, Germans, and Spanish, but also a few Americans and recent American immigrants. After 1930 a new vigor and bolder simplification appeared in his work. American art collector Albert C. Barnes convinced him to produce a large mural for the Barnes Foundation, The Dance II, which was completed in 1932. The Foundation owns several dozen other Matisse paintings.

He and his wife of 41 years separated in 1939. In 1941, he underwent surgery in which a colostomy was performed. Afterwards he started using a wheelchair, and until his death he was cared for by a Russian woman, Lydia Delektorskaya, formerly one of his models. With the aid of assistants he set about creating cut paper collages, often on a large scale, called gouaches découpés. His Blue Nudes series feature prime examples of this technique he called "painting with scissors"; they demonstrate the ability to bring his eye for colour and geometry to a new medium of utter simplicity, but with playful and delightful power.

In 1947 he published Jazz, a limited-edition book containing prints of colorful paper cut collages, accompanied by his written thoughts. In the 1940s he also worked as a graphic artist and produced black-and-white illustrations for several books and over one hundred original lithographs at the Mourlot Studios in Paris.

According to David Rockefeller, Matisse's final work was the design for a stained-glass window installed at the Union Church of Pocantico Hills near the Rockefeller estate north of New York City. "It was his final artistic creation; the maquette was on the wall of his bedroom when he died in November of 1954", Rockefeller writes. Installation was completed in 1956.

In 1951 Matisse finished a four-year project of designing the interior, the glass windows and the decorations of the Chapelle du Rosaire de Vence, often referred to as the Matisse Chapel. This project was the result of the close friendship between Matisse and Sister Jacques-Marie. He had hired her as a nurse and model in 1941 before she became a Dominican nun and they met again in Vence and started the collaboration, a story related in her 1992 book Henri Matisse: La Chapelle de Vence and in the 2003 documentary "A Model for Matisse".

He established a museum dedicated to his work in 1952, in his birthplace city, and this museum is now the third-largest collection of Matisse works in France. Matisse died of a heart attack at the age of 84 in 1954. He is interred in the cemetery of the Monastère Notre Dame de Cimiez, near Nice.