Shoumatoff was born in Kharkov, Ukraine, the daughter of a Russian general. Privately educated, she developed an interest in painting. In 1917, she came to the United States with her husband on a mission for the Russian government; they decided to remain after the Bolshevik Revolution, which occurred in October of that year. Upon her husband’s death, she began to paint professionally, primarily as a watercolorist.
Among her more than 3,000 portraits, Shoumatoff's sitters included the du Ponts, Fricks, Mellons, and other influential people of the twentieth century. However, it was a session with President Franklin D. Roosevelt that proved to be her most momentous. Shoumatoff was painting the president at his retreat in Warm Springs, Georgia when he collapsed from a cerebral hemorrhage in 1945, from which he never regained consciousness. FDR’s Unfinished Portrait, as the painting, and Shoumatoff’s memoir, came to be known, currently resides at the Little White House, where FDR died. Shoumatoff also painted President Lyndon B. Johnson, Lady Bird Johnson, and the Grand Ducal family of Luxembourg.