John Lloyd joined what was then the Computing Laboratory of Newcastle Unviersity as a postgraduate student in 1967, after obtaining a degree in Mathematics from the University of Manchester. He obtained a PhD in 1972.

He became a Research Officer in the Laboratory in 1970, and was promoted to a Lectureship in 1973 and to a Senior Lectureship in 1994. He became Head of the Department of Computing Science in 1997, and was Head of the School of Computing Science from its establishment in 2002 until 2006. From 2006 until 2008 he was Head of the School of Natural Sciences (subsequently the School of Chemistry). He has held visiting appointments at Northwestern University (1974) and at the University of Delaware (1985).

John's research interests, originally in numerical analysis, have extended to cover aspects of computer graphics and of parallel computation, particularly for numerical and graphics problems. He has taught a wide range of courses, and currently acts as external examiner for degree programmes at de Montfort University and for some overseas programmes of Staffordshire University. He remains a member of the BCS Academic Accreditation commitee and is a former secretary of the executive committee of the Council of Professors and Heads of Computing, the UK subject body for Computing.