Piyadassi Maha Thera (Sinhala: පියදස්සි මහා ස්ථවිරයන් වහන්සේ, 8 July 1914 – 18 August 1998) was a Theravādin Buddhist monk and preacher of the Dharma, both in Sinhalese and in English.

He was born on 8 July 1914 at Kotahena in Colombo, Sri Lanka and was educated at Nalanda College, Colombo, thereafter at the University of Sri Lanka and the Center for the Study of World Religions at Harvard University as a research student.

At the age of twenty, he entered the Buddhist monastic order under Pelene Siri Vajiragnana Nayaka Thera, founder of the Vajirarama Bambalapitiya.

[citation needed] Piyadassi Maha Thera was the Sinhala editor at the Buddhist Publication Society until his death.

[1] Along with Nyanaponika Thera, he was one of the chief kalyāṇamitta of American Buddhist scholar and monk Bhikkhu Bodhi.