This collective case study examines how four contemporary British scientists and popular science writers, Stephen Hawking, Richard Dawkins, Susan Greenfield and James Lovelock, are portrayed in mass media as celebrities. It finds that the scientists’ private and public lives merge in their representations, their images commodified and marketed by the cultural industries, their mediated personae embodying abstract ideas of truth and reason. The celebrity scientists base their authority on their scientific credentials, achieve public appeal through popularisation, particularly publishing popular science books, and speak in general culture on behalf of science. The subjects, to varying degrees, embody scientism as the supreme epistemology, but their public intellectual work is marked by a weak engagement with philosophical, cultural and sociological discourses. They engage with the cultural industries in the construction of their celebrity personae, and are criticised by their peers because their popular renown is considered to have eclipsed their internal scientific status. Using approaches from celebrity studies, science studies, biography, intellectual history and historiography of science, the study contextualises the celebrity scientists in late modern Britain, shaped by Thatcherism, Blairism, commercialism, globalisation, mediatisation, public science, and conceptions of the public intellectual. The subjects share characteristics with iconic historical scientists, including Isaac Newton, Charles Darwin, Albert Einstein, Fred Hoyle, Robert Oppenheimer, Rachel Carson, Carl Sagan and Stephen Jay Gould. The representations of the contemporary celebrity scientists feature associations with these famous historical figures, associations that provide cultural continuity to science and serve as a means of marketing modern scientist-authors. The four subjects each have a distinctive celebrity persona. Dawkins is the positivist atheist. Hawking is the disembodied genius. Lovelock is the environmentalist guru. Greenfield is the glamorous female scientist. The subjects are extreme examples of mediatisation in post-academic science, are protagonists in an increasingly commercialised era of public science, and have contributed to a richer general scientific culture.