Dreamscapes of Modernity offers the first book-length treatment of sociotechnical imaginaries, a concept originated by Sheila Jasanoff and developed in close collaboration with Sang-Hyun Kim to describe how visions of scientific and technological progress carry with them implicit ideas about public purposes, collective futures, and the common good. The book presents a mix of case studies—including nuclear power in Austria, Chinese rice biotechnology, Korean stem cell research, the Indonesian Internet, US bioethics, global health, and more—to illustrate how the concept of sociotechnical imaginaries can lead to more sophisticated understandings of the national and transnational politics of science and technology. A theoretical introduction sets the stage for the contributors’ wide-ranging analyses, and a conclusion gathers and synthesizes their collective findings. The book marks a major theoretical advance for a concept that has been rapidly taken up across the social sciences and promises to become central to scholarship in science and technology studies.