Dharmasiri Gamage was born on 4 October 1939, the only son to Maththaka Gamage Peter Appuhamy and Kalegana Arachchige Chandrawathi and the eldest brother to three sisters.

 

Gamage wrote his first lyrics Ho Mage Prema Matha in 1955 for Kala Suri G.S.B. Rani Perera who was a veteran singer in Sri Lanka and a programme producer of then Radio Ceylon (Sri Lanka Broadcasting Corporation) when he was just 16 years old. Gamage has written many more than 200 lyrics for Sinhala songs with music composed by music directors like Pandith W.D. Amaradeva, Premasiri Khemadasa and Rohana Weerasinghe and performed by various artists like Kala Suri G.S.B. Rani Perera, Pandith W.D. Amaradeva and Isharada Nanda Malini, and Haroon Lanthra.