Cull comes to USC from the University of Leicester in the United Kingdom, where he was a professor of American Studies and Director of the Centre for American Studies. His research and teaching interests are broad and inter-disciplinary, centering on the developing academic discipline of Public Diplomacy, the role of culture, information, news and propaganda in foreign policy. He is author of the forthcoming Selling America: US Information Overseas, a history of the U.S. Information Agency (Cambridge University Press 2005). His first book, Selling War, (Oxford University Press, 1995), was named by Choice Magazine as one of the ten best academic books of that year.

Cull earned both his B.A. and Ph.D. at the University of Leeds. While a graduate student he studied at Princeton University as a Harkness Fellow of the Commonwealth Fund of New York. From 1992 to 1997 he was lecturer in American History at the University of Birmingham.

He is the co-editor of Propaganda and Mass Persuasion: A Historical Encyclopedia, 1500-present (2003) which was one of Book List magazine’s reference books of the year, and co-editor of Alambrista and the U.S.-Mexico Border: Film, Music, and Stories of Undocumented Immigrants (2004). He is the president of the council of the International Association for Media and History, and has worked closely with the British Council's Counterpoint Think Tank.