Mark Rothko (/ˈrɒθkoʊ/ ^ⓘ ROTH-koh; Markus Yakovlevich Rothkowitz until 1940; September 25, 1903 – February 25, 1970) was an American abstract painter. He is best known for his color field paintings that depicted irregular and painterly rectangular regions of color, which he produced from 1949 to 1970. Although Rothko did not personally subscribe to any one school, he is associated with the American abstract expressionism movement of modern art.

Born to a Jewish family in Daugavpils, Latvia, then part of the Russian Empire, Rothko emigrated with his parents and siblings to the United States, arriving at Ellis Island in late 1913 and originally settling in Portland, Oregon. He moved to New York City in 1923 where his youthful period of artistic production dealt primarily with urban scenery. In response to World War II, Rothko's art entered a transitional phase during the 1940s, where he experimented with mythological themes and Surrealism to express tragedy. Toward the end of the decade, Rothko painted canvases with regions of pure color which he further abstracted into rectangular color forms, the idiom he would use for the rest of his life.

In his later career, Rothko executed several canvases for three different mural projects. The Seagram murals were to have decorated the Four Seasons Restaurant in the Seagram Building, but Rothko eventually grew disgusted with the idea that his paintings would be decorative objects for wealthy diners and refunded the lucrative commission, donating the paintings to museums including the Tate Gallery. The Harvard Mural series was donated to a dining room in Harvard's Holyoke Center (now Smith Campus Center); their colors faded badly over time due to Rothko's use of the pigment lithol red together with regular sunlight exposure. The Harvard series has since been restored using a special lighting technique. Rothko contributed 14 canvases to a permanent installation at the Rothko Chapel, a non-denominational chapel in Houston, Texas.

Although Rothko lived modestly for much of his life, the resale value of his paintings grew tremendously in the decades following his suicide in 1970. His painting No. 6 (Violet, Green and Red) sold in 2014 for $186 million.

Rothko was born in 1903 in Dvinsk (now Daugavpils, Latvia), a town within the Pale of Settlement in the Russian Empire. His father, Jacob (Yakov) Rothkowitz, was a pharmacist and intellectual who initially provided his children with a secular and political, rather than religious, upbringing. According to Rothko, his Marxist father was "violently anti-religious". In an environment where Jews were often blamed for many of the evils that befell Russia, Rothko's early childhood was plagued by fear.

Despite Jacob Rothkowitz's modest income, the family was highly educated ("We were a reading family", Rothko's sister recalled), and Rothko spoke Lithuanian Yiddish (Litvish), Hebrew and Russian. Following his father's return to the Orthodox Judaism of his own youth, Rothko, the youngest of four siblings, was sent to the cheder at age five, where he studied the Talmud, although his elder siblings had been educated in the public school system.

Fearing that his elder sons were about to be drafted into the Imperial Russian Army, Jacob Rothkowitz emigrated from the Russian Empire to the United States. Mark, then known as Markus, remained in the Russian Empire with his mother and elder sister Sonia. They arrived as immigrants, at Ellis Island, in late 1913. From there, they crossed the country, to join Jacob and the elder brothers, in Portland, Oregon. Jacob's death, a few months later, of colon cancer, left the family without financial support. Sonia operated a cash register, while Markus worked in one of his uncle's warehouses, selling newspapers to employees. His father's death also led Rothko to sever his ties with religion. After he had mourned his father's death for almost a year at a local synagogue, he vowed never to set foot in one again.

Rothko started school in the United States in 1913, quickly accelerating from third to fifth grade. In June 1921, he completed the secondary level, with honors, at Lincoln High School in Portland, Oregon, at age 17. He learned his fourth language, English, and became an active member of the Jewish community center, where he proved adept at political discussions. Like his father, Rothko was passionate about issues such as workers' rights and contraception.^{[citation needed]} At the time, Portland was a center of revolutionary activity in the U.S. and the region where the revolutionary syndicalist union Industrial Workers of the World (IWW) was active.^{[citation needed]}