Mohanlal Viswanathan Nair was born on 21 May 1960 in the Elanthoor village of Pathanamthitta district, Kerala, as the youngest child of Viswanathan Nair, a former bureaucrat and law secretary with the Kerala Government, and Santhakumari. He grew up at Mudavanmugal, Poojappura in Thiruvananthapuram. Mohanlal studied at Model School, Thiruvananthapuram, and graduated with a B.Com. from Mahatma Gandhi College in Thiruvananthapuram. Mohanlal received his first Best Actor Award when he was in sixth grade for a stage play called Computer Boy in which he enacted as a ninety-year-old person.
In 1977–78 he was the Kerala state wrestling champion.
Mohanlal lives with his family in Thevara, Kochi. He married Suchitra, daughter of Tamil film producer K. Balaji on 28 April 1988. Mohanlal later recalled in an interview that Suchitra used to send him cards because she wanted to marry him. Their horoscopes did not match at first, but later it was found that the astrologer erred. Mohanlal has two children – Pranav and Vismaya. Pranav has acted in a few movies, debuting in Mohanlal's film Onnaman. Mohanlal did not object when his son expressed a desire to act as "Kids may have many such ambitions. If we can help them realise something, what is the problem?" He owns a house at Ooty, a villa in Arabian Ranches and a flat in Burj Khalifa at Dubai. Mohanlal is a self-described foodie. He also enjoys melodious music. Mohanlal is a strong believer in destiny and spirituality. He likes to read Osho, J. Krishnamurti, Aurobindo and Ramana Maharshi. He has often stated that the turn of events in his life, including his film career, was accidental. His elder brother Pyarelal died in the year 2000, during a military exercise.