Hammond was educated at Peterhouse, Cambridge. He held academic positions at Cambridge (1967–75), Bradford (1975–77), and Rutgers universities (1977–88), before becoming a professor in the Archaeology Department at Boston University's College of Arts and Sciences (CAS) in 1988. Now Emeritus at Boston, he is currently a Senior Fellow of the McDonald Institute for Archaeological Research at Cambridge.
Since 1968, he has worked in the Maya lowlands at the following sites in Belize, Central America: Lubaantun (1970–1971), Nohmul (1973–1986), Cuello (1975–1986), and La Milpa (1992–2002). As well as specialising in the archaeology of Maya lowland sites in Belize, he has written on the emergence of complex societies in general, and on the history of archaeology.
He has served on the editorial boards of Ancient Mesoamerica and the Journal of Field Archaeology. He has also been the archaeology correspondent for The Times newspaper in London.
Hammond's published works include:
- Cuello: An Early Maya Community in Belize. Cambridge University Press, Cambridge and New York (1991).
- Ancient Maya Civilization. Cambridge University Press and Rutgers University Press. (1982, Fifth edition 1994)
- Lubaantun: A Classic Maya Realm. Peabody Museum of Archaeology and Ethnology, Harvard University, Monograph 2. Cambridge, MA (1975).
- "Birthdays". The Guardian. Guardian Media. 10 July 2014. p. 31.
- Boston University Office of University Relations 1998.
- BU Office of University Relations (25 September 1998). "Archaeology prof elected to British Academy" (online reproduction). B.U. Bridge. 2 (7). Brookline, MA: Boston University. OCLC 37915518. Retrieved 2009-03-25.
- McKillop, Heather I. (2004). The Ancient Maya: New Perspectives. Understanding ancient civilizations series. Santa Barbara, CA: ABC-CLIO. ISBN 1-57607-696-2. OCLC 52706645.