Cunliffe's decision to become an archaeologist was sparked at the age of nine by the discovery of Roman remains on his uncle's farm in Somerset. After studying at Portsmouth Northern Grammar School (now the Mayfield School) and reading archaeology and anthropology at the University of Cambridge, he became a lecturer at the University of Bristol in 1963. Fascinated by the Roman remains in nearby Bath he embarked on a programme of excavation and publication.
In 1966 he became an unusually young professor when he took the chair at the newly founded Department of Archaeology at the University of Southampton. There he became involved in the excavation (1961–68) of the Fishbourne Roman Palace in Sussex. Another site in southern England led him away from the Roman period. He began a long series of summer excavations (1969–88) of the Iron Age hill fort at Danebury, Hampshire and was subsequently involved in the Danebury Environs Programme (1989–95). His interest in Iron Age Britain and Europe generated a number of publications and he became an acknowledged authority on the Celts.
Other sites he has worked on include Hengistbury Head in Dorset, Mount Batten in Devon, Le Câtel in Jersey, and Le Yaudet in Brittany, reflecting his interest in the communities of Atlantic Europe during the Iron Age. In his later works he sets out the thesis that Celtic culture originated along the length of the Atlantic seaboard in the Bronze Age before being taken inland, which stands in contrast to the more generally accepted view that Celtic origins lie with the Hallstatt culture of the Alps. One of his most recent projects has been in the Najerilla valley, La Rioja, Spain, which straddles "the interface between the Celtiberian heartland of central Iberia and the Atlantic zone of the Bay of Biscay".
Cunliffe lives with his wife in Oxford.
Cunliffe inspired the name for the character "Currant Bunliffe", an archaeologist in David Macaulay's 1979 book, Motel of the Mysteries.
Positions and honours
- President, Council for British Archaeology (1976–79)
- Fellow, British Academy (1979)
- Member, Ancient Monuments Advisory Committee of English Heritage, since 1984
- Honorary Graduate, Doctor of Science, University of Bath (1984)
- Member, Advisory Committee of The Discovery Programme (Ireland), since 1991
- Trustee of the British Museum
- Governor, Museum of London
- Fellow, Society of Antiquaries of London
- Chair, Advisory Committee for the e-journal Internet Archaeology
- Cunliffe was knighted on 17 June 2006.
- Cunliffe was appointed interim chair of English Heritage in September 2008 
- Chairman, The British Museum Friends (-2009)
- Founding Fellow, The Learned Society of Wales
- The Roman Occupation, Introduction, Cumberland and Westmorland, The Buildings of England, Nikolaus Pevsner, Harmondsworth: Penguin (1967)
- Roman Hampshire, Introduction, Hampshire and the Isle of Wight, The Buildings of England, Nikolaus Pevsner, Harmondsworth: Penguin (1967)
- The Roman Occupation, Introduction, Worcestershire, The Buildings of England, Nikolaus Pevsner, Harmondsworth: Penguin (1968)
- Roman Kent, Introduction, North East and East Kent, The Buildings of England, Nikolaus Pevsner, Harmondsworth: Penguin (1969)
- Fishbourne: A Roman Palace and Its Garden (1971)
- The Regni (1973) in the 'Peoples of Roman Britain series Ed.Keith Brannigan, pub. Duckworth (1973) ISBN 0-7156-0699-9
- Iron Age Communities in Britain (1974) ISBN 0-7100-8725-X (4th edition, Jan 2005)
- Excavations in Bath 1950-1975 (1979)
- Danebury: Anatomy of an Iron Age Hillfort (1983)
- Roman Bath Discovered (1984)
- The Celtic World (1987)
- Greeks, Romans and Barbarians (1988)
- Wessex to AD 1000 (1993)
- The Ancient Celts (1997) ISBN 0-14-025422-6
- Facing the Ocean: The Atlantic and Its Peoples, 8000 BC to AD 1500 (2001, Oxford University Press)
- The Oxford Illustrated History of Prehistoric Europe (2001)
- The Extraordinary Voyage of Pytheas the Greek: The Man Who Discovered Britain (2001), Walker & Co; ISBN 0-8027-1393-9 (2002 Penguin ed. with new post-script: ISBN 0-14-200254-2)
- The Celts: A Very Short Introduction (2003), Oxford University Press
- England's Landscape: The West (English Heritage 2006)
- Europe Between the Oceans: 9000 BC-AD 1000 (2008) ISBN 0-300-11923-2
- A Valley in La Rioja: The Najerilla Project, with Gary Lock (Oxford Univ School of Archaeology 2010)
- Druids: A Very Short Introduction (2010), Oxford University Press
- Celtic from the West. Alternative perspectives from archaeology, genetics and literature. (Oxford: Oxbow Books). 2010.
- Britain Begins (Oxford University Press 2012)
- By Steppe, Desert, and Ocean: The Birth of Eurasia (Oxford University Press 2015)
- History Today, vol 50, issue #9 "Digging for Joy"
- publisher notes, Cunliffe, B, Lock, G, A Valley in La Rioja: The Najerilla Project
- "Honorary Graduates 1989 to present". bath.ac.uk. University of Bath. Retrieved 18 February 2012.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Honours: 'Jewel in the Crown' star appointed OBE. The Independent. 17 June 2006. Accessed 2 October 2008.