Jeffery John Orchard was educated at Alleyn's School, Dulwich and King's College Cambridge where he graduated with First Class Honours in Part II of the Archaeology and Anthropology Tripos. This was followed by National Service in the army, during which he learned Russian at the Joint Services School for Linguists. This was always a keenly sought-after option for servicemen as a relief from the atavistic grimness of basic training, and the selection procedure was consequently tough and weekly testing unrelenting. Following successful completion of the course, Jeffery was promoted to Second Lieutenant (Russian Translator) in the Intelligence Corps.

At the end of his National Service in 1956, he was appointed Assistant Keeper of Egyptian and Western Asiatic Antiquities at the Ashmolean Museum, Oxford and there participated in the re-design of the Egyptian galleries with their new thematic interpretations. In 1961, Sir Max Mallowan invited him to become the Assistant Director of the British School of Archaeology in Iraq, Baghdad, where, amongst other duties, he oversaw the cataloguing and initial conservation of the almost overwhelmingly large and magnificent collection of ivories excavated at Nimrud, himself directing a significant season of work at the site. Jeffery's eye for detail and careful, methodical approach made him particularly well equipped to work on the often extremely fragmentary ivories as his resultant exceptionally clear and authoritative catalogue of ivory harness elements showed.

In 1971, Jeffery was appointed Lecturer in the Ancient History and Archaeology of Western Asia at the University of Birmingham. Jeffery was a natural and gifted teacher at a time when actually helping students to learn seemed almost to be frowned upon. Approachable, friendly and always helpful, generations of students at Birmingham chose “Mesopotamian Studies” because of Jeffery and were lucky to do so. Jeffery's lectures and seminars were masterpieces of research and thorough preparation. His finely drafted papers, delivered with a quiet and wryly understated sense of humour, provided everything that even the most inattentive student needed to understand the subject and to pass (though likely few realised it at the time).

In the late 1970s, Jeffery was determined to return to fieldwork and his first plan was to select a site in the Syrian Jazirah where sites such as Tell Leilan and Tell al-Rimah were producing many new discoveries. The Syrian authorities were welcoming and even offered a division of the finds but, with three British teams already working in Syria, the rationale for another expedition was uncertain and the competition for funding and resources was clearly going to be counter-productive and difficult. By contrast, the Sultanate of Oman offered fresh and exciting opportunities for work, and in this newly emerging field of research, money and aid-in-kind were, at the time, more generally available and generous.

Between 1980 and 2013, Jeffrey directed, with his wife, Jocelyn, the University of Birmingham Archaeological Expedition to the Sultanate of Oman (now The Hajar Project). Under the patronage of the Oman Ministry of Heritage and Culture, this was active fieldwork to investigate in detail the character of a large area of the Wadi Bahla, exploring oasis settlement from many perspectives, archaeological and ethnographic from the late fourth millennium b.c. to the present. At the time of his death, Jeffery was engaged in preparing the final publication of this more than thirty years of work.