Baker grew up fatherless and in poverty. Between the ages of 8 and 10 she was out of school, helping to support her family. As a child Baker developed a taste for the flamboyant that was later to make her famous. As an adolescent she became a dancer, touring at 16 with a dance troupe from Philadelphia. In 1923 she joined the chorus in a road company performing the musical comedy Shuffle Along and then moved to New York City, where she advanced steadily through the show Chocolate Dandies on Broadway and the floor show of the Plantation Club.

In 1925 she went to Paris to dance at the Théâtre des Champs-Élysées in La Revue Nègre and introduced her danse sauvage to France. She went on to become one of the most popular music-hall entertainers in France and achieved star billing at the Folies-Bergère, where she created a sensation by dancing seminude in a G-string ornamented with bananas. She became a French citizen in 1937. She sang professionally for the first time in 1930, made her screen debut as a singer four years later, and made several more films before World War II curtailed her career.

During the German occupation of France, Baker worked with the Red Cross and the Résistance (resistance), and as a member of the Free French forces she entertained troops in Africa and the Middle East. She was later awarded the Croix de Guerre and the Legion of Honour with the rosette of the Résistance. After the war much of her energy was devoted to Les Milandes, her estate in southwestern France, from which she began in 1950 to adopt babies of all nationalities in the cause of what she defined as “an experiment in brotherhood” and her “rainbow tribe.” She retired from the stage in 1956, but to maintain Les Milandes she was later obliged to return, starring in Paris in 1959. She traveled several times to the United States to participate in civil rights demonstrations. In 1968 her estate was sold to satisfy accumulated debt. She continued to perform occasionally until her death in 1975, during the celebration of the 50th anniversary of her Paris debut.