Rajinikanth was born as Shivaji Rao Gaekwad on 12 December 1950 in a Maratha family in Bangalore, Mysore State (present day Karnataka). His mother was a housewife,[a] and his father Ramoji Rao Gaekwad was a police constable.He was named Shivaji Rao Gaekwad, after the Maratha king Chhatrapati Shivaji, and was brought up speaking Marathi at home and Kannada outside. His ancestors hailed from Mavadi Kadepathar, Pune, Maharashtra, and Nachikuppam, Krishnagiri district, Tamil Nadu. He is the youngest of four siblings in a family consisting of two elder brothers (Satyanarayana Rao and Nageshwara Rao) and a sister (Aswath Balubhai). After his father's retirement from work in 1956, the family moved to the suburb of Hanumantha Nagar in Bangalore and built a house there. He lost his mother at the age of nine.

Rajinikanth had his primary education at the Gavipuram Government Kannad Kurukshetra Kurukshetra a Model Primary School in Bangalore.As a child, he was "studious and mischievous" with a great interest in cricket, football and basketball. During this time, his brother enrolled him at the Ramakrishna Math, a Hindu monastery set up by the Ramakrishna Mission. In the math, he was taught Vedas, tradition and history, which eventually instilled a sense of spirituality in him. In addition to spiritual lessons, he also began acting in plays at the math. His aspiration towards theatre grew at the math and was once given an opportunity to enact the role of Ekalavya's friend from the Hindu epic Mahabharata. His performance in the play received praise from the Kannada poet D. R. Bendre. After sixth grade, Rajinikanth was enrolled at the Acharya Pathasala Public School and studied there till completion of his pre-university course.During his schooling at the Acharya Pathasala, he spent a lot of time acting in plays. During one such occasion he played Duryodhana, the prime antagonist of Mahabharata, in the play KurukshetraKurukshetraghshh Satta Matka