Sreekumaran Thampi was born in Harippad, Alappuzha District on 16 March 1940 to Kalarikkal Krishna Pillai (from Thonnackad near Mavelikara ) and Karimpalayathu Bhavaniamma Thangachi ( related to Haripattu Koikkal, the Royal House ). He is a graduate in mathematics from Sanatana Dharma College,Alappuzha and civil engineer, graduated from Institute of Engineering Technology, Chennai and Govt. Engineering College, Thrissur.
His siblings are the novelist late P. Vasudevan Thampi who wrote Sreekrishnaparinthu (which became a hit Malayalam film), late Advocate P. Gopalakrishnan Thampi, the former Director General of Prosecutions (Kerala), and former Chairman of Kerala Bar Council, Thulasibhai Thankachi and Prasannavadanan Thampi, former Vice President of Oracle Financial Systems Software Ltd
Thampi is married to Rajeswari, the daughter of Vaikom M. P.Mani, a popular drama actor and singer of 1930's and 1940's, and they have a daughter (Kavitha). His wife and daughter have also dabbled in the arts. He also had a son, Rajkumaran Thampi (also known as Raj Aditya) was an erstwhile associate of Priyadarshan and later directed some movies in the Telugu film industry, until his sudden death in Secundarabad in March 2009. According to Thampi, he could not sleep after his son's death without the help of sleeping pills.