Born in Cambridge, Osbert was the only child of biologist John Edmund Sharrock Moore and Heloise Moore. He was named after Heloise's father, the naturalist Osbert Salvin. He studied modern languages at Exeter College, Oxford. He helped a friend to run an antiques shop before joining the army at the outbreak of World War II, joining the anti-aircraft regiment before being transferred to the Intelligence Corps officer-cadet training camp. He was posted to a camp on the Isle of Man to help oversee Italian internees. In 1944 he was posted to Italy serving as an intelligence officer interrogating spies and saboteurs. During this period he discovered Buddhism via Julius Evola's The Doctrine of Awakening a Nietzschean interpretation of Buddhism. This work had been translated by his friend Harold Edward Musson, also an intelligence officer serving in Italy. After the war Moore joined the Italian section of the BBC. Moore and Musson, who shared a flat in London, were quite disillusioned with their lives and left to Sri Lanka in 1949 to become Buddhist monks. On 24 April 1949 they received the novice ordination or going forth, pabbajjā, from Ñatiloka at the Island Hermitage. In 1950 they received their bhikkhu ordination at Vajirarama Temple Colombo. Ñāṇamoli spent almost his entire monk life of eleven years at the Island Hermitage. After having been taught the basics of Pali by Nyanatiloka Mahathera, Ñāṇamoli acquired a remarkable command of the Pali language and a wide knowledge of the canonical scriptures within a comparatively short time. He is remembered for his reliable translations from the Pali into English, mostly of abstruse texts such as the Nettippakaraṇa which are considered difficult to translate. He also wrote essays on aspects of Buddhism. By 1956 he had translated Visuddhimagga into English and got it published as The Path of Purification. He also compiled The Life of the Buddha, a reliable and popular biography of the Buddha based on authentic records in the Pali Canon. His notes with his philosophical thoughts were compiled by Nyanaponika Thera and published as A Thinker's Note Book. His handwritten draft translation of the Majjhima Nikaya was typed out after his death and edited by Bhikkhu Khantipalo, and partly published as A Treasury of the Buddha's Discourses and then edited again by Bhikkhu Bodhi and published as Middle Length Length Discourse of the Buddha and published by Wisdom Publications in 1995. Other draft translations, edited and published after his death, are The Path of Discrimination and Dispeller of Delusion . While on a pilgrimage he died suddenly due to heart failure at the hamlet of Veheragama near Mahawa. His body was brought to Vajirarama Temple in Colombo and cremated at a nearby cemetery.
The Life of the Buddha: as it appears in the Pali Canon, the oldest authentic record. First printing 1972, fifth printing 2007.
The Practice of Loving-kindness : as taught by the Buddha in the Pali Canon. Compiled and translated 1958. Published in The Wheel No. 6/7. First printing 1958. Sixth reprint 2005.
A Pali-English Glossary of Buddhist Technical Terms. Edited by Bhikkhu Bodhi. First edition 1991. Second edition 2007.
Three Cardinal Discourses of the Buddha: Translation with Introduction and Notes. First printing 1960; third reprint 1981 as The Wheel No. 17.
Pathways of Buddhist Thought: Four Essays. 1963, 1983—.
“Anicca-Dukkha-Anatta. According to the Theravāda.” Three Essays in The Three Basic Facts of Existence, 1973–74.
A Thinker’s Notebook: Posthumous Papers of a Buddhist Monk. Compiled by Nyanaponika Thera. First edition 1972. Second edition: 1980. Third edition, including Pathways of Buddhist Thought, and the previously unpublished essay 'The Sukkhavipassaka', 2008.