Flowers is the son of Arthur R. Flowers, Sr., a medical doctor and bridge player of national rank, and Eloise Flowers, a nurse and teacher. He was born in Memphis, Tennessee, where he was immersed in the American Civil Rights movement from an early age. In high school, he developed a reputation for intelligence, earning the nickname "Mr. Brain", and for radicalness, earning the nickname "Bullet" because of the bullet he wore on a necklace. In 1968, he attended Martin Luther King Jr.’s final speech, and then led his high school class in a walkout after King's assassination. According to Flowers, "we charged the police and got into all kinds of riots".