Drewett was brought up in Croydon, where he first became interested in archaeology; he began working on excavations in his early teens, joining the Croydon Natural History and Scientific Society in 1960. Drewett later worked on digs in Sussex, and in 1973 joined Sussex Archaeological Society. After graduating, he became a lecturer at the London Institute of Archaeology and founded the Sussex Archaeological Field Unit (now Archaeology South-East), subsequently being involved in over 200 projects in the county. Sites he worked on included Caburn hillfort, Black Patch and Chanctonbury Ring. He obtained his Ph.D. in Prehistoric Archaeology from the Institute of Field Archaeology in 1986.
Professor Drewett also worked on excavations overseas, including Barbados and the British Virgin Islands. At the time of his death, he was Emeritus Professor at Sussex University's Centre for Community Engagement.
- 1991: Prehistoric Barbados
- 1999: Field Archaeology: an introduction
- 1999: The South East to AD 1000 (Regional History of England; with D. Rudling and M. Gardiner)
- 2000: Prehistoric Settlements in the Caribbean: Fieldwork in Barbados, Tortola and the Cayman Islands
- 2007: Above Sweet Waters: Cultural and Natural Change at Port St. Charles, Barbados, c. 1750 BC - AD 1850
- John Manley, "Peter Ladson Drewett 1947-2013", Sussex Past & Present, August 2013, p.11
- Sussex Archaeological Society - Black Patch Project. Accessed 3 August 2013
- UCL Institute of Archaeology - Peter Drewett (1947-2013), 5 April 2013. Accessed 3 August 2013
- The Times Obituaries: Professor Peter Drewett, 9 May 2013. Accessed 3 August 2013