Bethell is Member of the Brazilian Center for International Relations (CEBRI)'s International Advisory Board. He is an Emeritus Professor of Latin American History and a former Director of the Institute of Latin American Studies, University of London; Emeritus Fellow, St Antony’s College, Oxford and founding Director of the Centre for Brazilian Studies, University of Oxford.

He is the author of numerous books and articles on the political, social and cultural history of Latin America, focusing especially on Brazil, most recently publishing Joaquim Nabuco no mundo: abolicionista, jornalista e diplomata ("Joaquim Nabuco in the World: Abolitionist, Journalist and Diplomat") (2016), (ed.) Viva la Revolución. Eric Hobsbawm on Latin America (2016), and Brazil: Essays in History and Politics (2018).

He is an Editor of the 12-volume Cambridge History of Latin America, also published in Spanish, Portuguese and Chinese. In 2010, he was elected one of twenty foreign members of the Brazilian Academy of Letters and was awarded the Ordem Nacional do Mérito Científico (National Order of Scientific Merit).