Mahanati depicts the personal and professional life of first Indian female superstar, Savitri. After actress Savitri is admitted in a hospital in Bangalore and she goes into coma, a young investigative journalist, Madhuravani, seizes the opportunity to write an article on her life. The young Savitri meets Gemini Ganesan, who works in casting department, after her failed attempts to get a role in cinema. They both start a career in acting and eventually rise to stardom. Savitri falls in love with him despite the fact that he is married. Their marriage results in a rift with her family but Savitri never gives up on her love. Her dreams are shattered when she learns that Gemini Ganesan is a womanizer and has been continuing his illicit relationships even after their marriage. The rest of the story is about how she stood up against all odds and the result of her wrong choices in life.