Was born on July 3, 1978 in Nugegoda as the second of the family with two siblings. He started education at Ashoka Vidyalaya, Maradana. After passing grade 5 scholarship examination, he went to Ananda College. At school, Sahan was the Chairman of Drama Society and the Treasurer of Broadcasting Unit. He did A/L from commerce stream and selected to the University of Colombo. His elder brother Chirantha is a television announcer and also an actor.
His father Lionel Ranwala was an icon in Sri Lanka music industry who performed folk music in Sri Lanka. Lionel is the founder of Ranwala Balakaya. Sahan is a graduate from Drama and Theater at University of Kelaniya. He also has a Diploma in Journalism at the University of Sri Jayewardenepura and degree from Sri Lanka Law College