Rekha was born in Madras on 10 October 1954 to Tamil actor Gemini Ganesan and Telugu actress Pushpavalli. Rekha has a sister, one half-brother and five half-sisters. It was in early 1970s, when she was looking for a footing in Bollywood, that she revealed her origins. Later, at the peak of her career, Rekha told a magazine interviewer that her father’s neglect still rankled and that she had ignored his efforts at reconciliation. Rekha attended Sacred Heart Convent for Girls in Yercaud, Tamil Nadu.
At the age of 13, she quit school to start a career in acting. She did not have any personal aspirations in this direction, but the troubled financial state of her family compelled her to do so. She considers Telugu to be her mother tongue. She has stated that she thinks in English. Rekha made her debut as heroine in the successful Kannada film Operation Jackpot Nalli C. She had no interest in acting and was basically forced to work to sustain her family financially, this was a difficult period in her life. Still a teenager, acclimatising herself to her new surroundings was an uneasy process.