Bonnie Elizabeth Parker was born in 1910 in Rowena, Texas, the second of three children. Her father, Charles Robert Parker (1884-1914), was a bricklayer who died when Bonnie was four years old. Her widowed mother, Emma (Krause) Parker (1885-1944), moved her family back to her parents' home in Cement City, an industrial suburb in West Dallas where she worked as a seamstress. As an adult, Bonnie wrote poems such as "The Story of Suicide Sal" and "The Trail's End", the latter more commonly known as "The Story of Bonnie and Clyde".

Parker was a bright child who thrived on attention. She enjoyed performing on stage and dreamt of becoming an actress. In her second year in high school, Parker met Roy Thornton (1908-1937). The couple dropped out of school and married on September 25, 1926, six days before her 16th birthday. Their marriage was marred by his frequent absences and brushes with the law and proved to be short-lived. They never divorced, but their paths never crossed again after January 1929. Parker was still wearing the wedding ring Thornton had given her when she died. Thornton was in prison when he heard of her death, commenting, "I'm glad they jumped out like they did. It's much better than being caught." Sentenced to five years for robbery in 1933 and after attempting several prison breaks from other facilities, Thornton was killed while trying to escape from the Huntsville State Prison on October 3, 1937.

After she left Thornton, Parker moved back in with her mother and worked as a waitress in Dallas. One of her regular customers was postal worker Ted Hinton. In 1932, he joined the Dallas County Sheriff's Department and eventually served as a member of the posse that killed Bonnie and Clyde. Parker briefly kept a diary early in 1929 when she was aged 18, writing of her loneliness, her impatience with life in Dallas, and her love of photography.