Photographers are often inspired by politics but can they influence it? Drawing on the study of public policy and the history of photography, this article considers three ways in which documentary photographers enter the policy process. It considers the photographer as: a bureaucrat working within government networks to achieve individual and institutional aims; an advocate working with like-minded actors to advance shared political beliefs; an expert working within an epistemic community driven by a shared policy enterprise. These roles highlight the institutional channels through which photographers seek and sometimes secure political change and the contradictions and constraints they face in so doing. These contrasting perspectives are discussed with reference to the work of canonical and contemporary photographers engaged in national and international politics from 1890 to today.