Lena Baker was born on June 8, 1900, in Cuthbert, Georgia. She came from a family of sharecroppers and had three siblings. When Lena was a child, her family moved to the county seat of Randolph County. They worked hard as farm laborers. As a young girl, Lena chopped cotton for a local farmer named J.A. Cox.

By the 1940s, Lena had become a mother of three children. To support her family, she worked as a maid. Her early life involved many struggles, typical for families who worked in agriculture during that time. Despite the challenges, she continued to care for her children while managing her job.

In 1944, Lena Baker began working for Ernest Knight, an older white man who owned a gristmill. Baker was in a difficult situation, as Knight sexually assaulted her and kept her imprisoned for days. People in the town, including Knight's son, did not like their relationship and often threatened Baker. One night, an argument broke out between Baker and Knight. During the argument, Knight threatened her with an iron bar. As Baker tried to escape, they struggled over Knight's pistol, and she shot him, claiming it was self-defense.

Baker reported the incident to the authorities, describing the struggle that led to Knight's death. Later, she was charged with capital murder and went on trial on August 14, 1944. The trial was overseen by Judge William Worrill. At the trial, Baker explained how Knight had forced her to return to him that Saturday evening and how she had previously suffered abuse from him and his son. Despite her claims of self-defense, an all-white, all-male jury convicted her by the end of the first day, sentencing her to death.

Governor Ellis Arnall later granted Baker a 60-day reprieve to allow a review of her case by the Board of Pardons and Parole. However, in January 1945, her request for clemency was denied. On February 23, 1945, she was transferred to Georgia State Prison. Lena Baker was executed by electrocution on March 5, 1945. After her death, she was buried in an unmarked grave behind Mount Vernon Baptist Church.

In 1998, some members of her church arranged for a headstone for her grave. In 2003, her family began to honor her memory on the anniversary of her death. Two years later, the Parole Board granted Baker a full and unconditional pardon, recognizing the injustices she faced during her trial and execution.