[[Image:Ajaan Geoff Almsround.jpg|thumb|left|Ajaan Geoff going on almsround(photo by Sakula (Mary Reinard))]]

?h?nissaro Bhikkhu was born Geoffrey DeGraff in 1949 and was introduced to the Buddha's teaching on the Four Noble Truths as a high schooler, during a plane ride from the Philippines. After graduating in 1971 with a degree in European Intellectual History from Oberlin College, he travelled to Thailand, where he practiced meditation under Ajaan Fuang Jotiko, who'd studied under Ajaan Lee. He ordained in 1976 at Ajaan Lee's Wat Asokaram where Ajaan Lee's nephew, Ajaan Tawng Jandasiri, served as Preceptor for his ordination. Later, he took residence at Wat Dhammasathit in Thailand.

Before Ajaan Fuang's death in 1986, he expressed his wish for Ajaan Geoff to become abbot of the monastery in Thailand. Some time after his teacher's death, he was offered the position of abbot, but with "strings... attached" and no authority since he was a Westerner in a monastery founded by and for Thai monks. Instead of accepting that position, he travelled to San Diego County in 1991, upon request of Ajaan Suwat Suvaco, where he helped him start Metta Forest Monastery. He became abbot of the monastery in 1993. In 1995, Ajaan Geoff became the first American born, non-Thai bhikkhu to be given the title, authority and responsibility of Preceptor (Uppajaya) in the Dhammayut Order. He also served as Secretary General of that Order for all of North America.

His extensive list of publications includes:

• Translations of Ajaan Lee's meditation manuals from the Thai
• Handful of Leaves, a five-volume anthology of sutta translations
• The Buddhist Monastic Code, a two-volume reference handbook for monks
• Wings to Awakening, a collection of some of the Buddha's most essential teachings
• The Mind Like Fire Unbound, an examination of Buddhism in terms of contemporary philosophies of fire
• The Paradox of Becoming, an extensive analysis on the topic of becoming as a causal factor of stress and suffering
• The Karma of Questions, Noble Strategy, and Purity of Heart, collections of essays on Buddhist practice
• Meditations (1-4), collections of transcribed Dhamma talks
• Dhammapada: A Translation, a collection of verses by the Buddha
• (As co-author) the college-level textbook, Buddhist Religions: A Historical Introduction

Besides Buddhist Religions, all of the books mentioned above are for free distribution, many of which can be read or downloaded in digital format online. Also freely available are audio recordings of many of his Dhamma Talks.

Metta Forest Monastery, Portland Friends of Dharma, The Cambridge Insight Meditation Center