Nyanaponika Thera or Nyanaponika Mahathera (July 21, 1901 – 19 October 1994) was a German-born Sri-Lanka-ordained Theravada monk, co-founder of the Buddhist Publication Society, contemporary author of numerous seminal Theravada books, and teacher of contemporary Western Buddhist leaders such as Bhikkhu Bodhi.
Ven. Nyanaponika Thera (Siegmund Feniger) was born in Hanau, Germany on July 21, 1901 as Siegmund Feniger, the only child of a Jewish family.
In 1922, he moved with his parents to Berlin, where he met with other German Buddhists and also had access to Buddhist literature in German language. He first came across the writings of Ven. Nyanatiloka Thera (1878–1957), the former German violin virtuoso Anton Gueth, which had already been published in Germany. Young Siegmund had learned Ven. Nyanatiloka Thera had established a monastery for Western Monks on an island lagoon (opposite the Railway station) Polgasduwa, Dodanduwa named Island Hermitage. This news stirred his conscience to go to Asia and become a Buddhist Monk.