Kazimir Severinovich Malevich (23 February [O.S. 11 February] 1879 – 15 May 1935) was a Russian avant-garde artist and art theorist, whose pioneering work and writing influenced the development of abstract art in the 20th century. His concept of Suprematism sought to develop a form of expression that moved as far as possible from the world of natural forms (objectivity) and subject matter in order to access "the supremacy of pure feeling" and spirituality. Born in Kiev, modern-day Ukraine, to an ethnic Polish family, Malevich was active primarily in Russia and became a leading artist of the Russian avant-garde. His work has been also associated with the Ukrainian avant-garde, and he is a central figure in the history of modern art in Central and Eastern Europe more broadly.

Early in his career, Malevich worked in multiple styles, assimilating Impressionism, Symbolism, Fauvism, and Cubism through reproductions and the works acquired by contemporary Russian collectors. In the early 1910s, he collaborated with other avant-garde Russian artists, including Mikhail Larionov and Natalia Goncharova. After World War I, Malevich gradually simplified his approach, producing key works of pure geometric forms on minimal grounds. His abstract painting Black Square (1915) marked the most radically non-representational painting yet exhibited and drew "an uncrossable line (…) between old art and new art". Malevich also articulated his theories in texts such as From Cubism and Futurism to Suprematism (1915) and The Non-Objective World (1926).

His trajectory mirrored the upheavals around the October Revolution of 1917. In 1918, Malevich began teaching in Vitebsk along with Marc Chagall. In 1919, he founded the UNOVIS artists collective and had a solo show at the Sixteenth State Exhibition in Moscow in 1919. His reputation spread westward with solo exhibitions in Warsaw and Berlin in 1927. This marked the first and only time Malevich ever left Russia. From 1928 to 1930 he taught at the Kiev Art Institute alongside Alexander Bogomazov, Victor Palmov, and Vladimir Tatlin, while publishing in the Kharkiv magazine Nova Generatsiia (New Generation). Repression of the intelligentsia soon forced him back to Leningrad. By the early 1930s, Stalin's restrictive cultural policy and the subsequent imposition of Socialist Realism had prompted Malevich to return to figuration and to paint in a representational style. Diagnosed with cancer in 1933, he was not allowed to leave the Soviet Union to seek treatment abroad. While constrained by his progressing illness and Stalin's cultural policies, Malevich painted and exhibited his work until his death. He died from cancer on 15 May 1935, at age 56.

His art and his writings influenced Eastern and Central European contemporaries such as El Lissitzky, Lyubov Popova, Alexander Rodchenko and Henryk Stażewski, as well as generations of later abstract artists, such as Ad Reinhardt and the Minimalists. He was celebrated posthumously in major exhibits at the Museum of Modern Art (1936), the Guggenheim Museum (1973), and the Stedelijk Museum in Amsterdam (1989), which has a large collection of his work. In the 1990s, the ownership claims of museums to many Malevich works began to be disputed by his heirs.

Kazimir Severinovich Malevich was born on either 23 (O.S. 11) February or 26 (O.S. 14) February 1879, to Severin (Seweryn) Antonovich and Liudviga (Ludwika) Alexandrovna. His parents, who were Polish, had fled Poland following the failed January Uprising of 1863 against Russian rule. Lucjan Malewicz, Kazimir's uncle, was a Catholic priest and one of the leaders of the 1863 insurrection. The family subsequently settled near Kiev (modern-day Kyiv, Ukraine) in Kiev Governorate of the Russian Empire. Kazimir was the first of fourteen children, only nine of whom survived into adulthood. His parents were Roman Catholic, though his father attended Orthodox services as well. The primary language spoken within Malevich's household was Polish, but he also spoke Russian, as well as Ukrainian due to his childhood surroundings.

Malevich's father worked as manager at several different sugar refineries. Between 1889 and 1896, Malevich's family relocated multiple times due to his father's job. In 1889, they moved to Parkhomovka near Kharkov (modern-day Ukraine). In Parkhomovka, Malevich attended a two-year agricultural school and taught himself to paint in a simple peasant style, drawing inspiration from rural surroundings. About four years later, the family relocated to Voltochok near Konotop, which was near centers of Polish cultural activity at the time. There, Malevich met the composer Nikolai Roslavets. He later briefly attended classes at the Kiev School of Drawing under the encouragement of the realist painter Mykola Pymonenko.

In 1896, the family moved to Kursk (modern-day Russia), where Malevich encountered several Russian artists, such as Lev Kvachevsky, with whom he often worked outdoors. By Malevich's own admission, his dedication to painting would make him the "black sheep" of the family. Through reproductions, Malevich also became familiar with the work of the Peredvizhniki (Wanderers), including Ivan Shishkin and Ilia Repin, two leading Russian Realist painters. In 1896, he began working as a technical draughtsman at the Moscow-Kursk-Voronezh railway company.

Malevich would later describe 1898 as the year he began exhibiting his work, although there is no evidence for this claim. In 1899, he met his first wife, Kazimira Ivanovna Zgleits, who was eight years his senior. They had two children, Galina and Anatolii, the latter of whom dies of typhoid in his early childhood. His father died in 1902, at the age of fifty-seven, and in 1903, Malevich held an exhibition at the Society for the Support of Primary Education in Kursk.