Cullen earned his Ph.D. in Sociology from Columbia University. He has held numerous prestigious academic positions throughout his career, most notably as a Professor of Criminal Justice at the University of Cincinnati, where he is currently a Distinguished Research Professor Emeritus. His career also includes significant leadership roles within the academic community. He served as President of the American Society of Criminology (ASC) in 1994 and as Editor of Criminology, the flagship journal of the ASC, from 1995 to 1998.
His research has significantly influenced theoretical developments, empirical studies, and policy discussions in criminology. He is a key proponent of social support theory, which posits that social support can act as a protective factor against crime and deviance, and he has extensively explored its implications for crime prevention and offender rehabilitation. He has also conducted extensive empirical work applying and testing various criminological theories, often in collaboration with other prominent scholars such as Robert Agnew and John Paul Wright. His work has contributed to a deeper understanding of the causes of crime, the effectiveness of various criminal justice interventions, and the experiences of victims.
Among his numerous accolades, Cullen received the Edwin H. Sutherland Award from the American Society of Criminology in 2011, which is the society's highest honor for scholarly contributions. He has also been recognized with the ASC's Lifetime Achievement Award for his exceptional contributions to criminological scholarship and mentorship. A prolific author, he has published dozens of books and hundreds of journal articles and book chapters that continue to shape the discourse in criminology and guide future research.