Kadawedduwe Sri Jinavamsa Mahathera (Pali: Siri Jinavaṃsa, sometimes spelled Jinawansa) was a Sri Lankan Bhikkhu (Buddhist monk). He was the founder of Sri Kalyani Yogasrama Samstha, a reform movement within the Sri Lankan Rāmañña Nikāya.
Ven. Jinavamsa Mahathera was born Don Dinesh on 1 April 1907 in the Kadawedduwa village in Matara. He was the fourth and youngest child in the family. Don Dinesh had his primary education at the Yatiyana Vernacular School.
When Dinesh was 10 years old, he was invited to stay and attend upon Ven. Kadawedduwe Siri Sugunatissa Mahathera, the elder brother of Dinesh's father and the abbot of Srivardhanaramaya, a temple in Yatawara. There, Dinesh learnt Pali and Sanskrit from the Ven. Kothmale Siri Saddhammavamsa Mahathera. In 1921, at the age of 14, Don Dinesh received Pabbajja with the name Kadawedduwe Jinavamsa, with Ven. Sugunatissa Mahathera as his Upajjhaya. In 1927, at the age of 20, Ven. Jinavamsa received Upasampada, with Ven. Sri Ñāṇindasabha Mahathera as his preceptor.
In 1932, Ven. Jinavamsa founded the ‘Granthakara Pirivena’ with 5 students. Later it was registered as a grant aided Pirivena under the Government on the recommendation of C.