Drawing on 48 in-depth interviews conducted with biologists and physicists at universities in the United Kingdom, this study examines scientists’ perceptions of the role celebrity scientists play in socially contentious public debates. We examine Richard Dawkins’ involvement in public debates related to the relationship between science and religion as a case to analyze scientists’ perceptions of the role celebrity scientists play in the public sphere and the implications of celebrity science for the practice of science communication. Findings show that Dawkins’ proponents view the celebrity scientist as a provocateur who asserts the cultural authority of science in the public sphere. Critics, who include both religious and nonreligious scientists, argue that Dawkins misrepresents science and scientists and reject his approach to public engagement. Scientists emphasize promotion of science over the scientist, diplomacy over derision, and dialogue over ideological extremism.