 Since the 1970s, studies of risk have grown into a major interdisciplinary field of research. Although relatively few philosophers have focused their work on risk, there are important connections between risk studies and several philosophical subdisciplines. This entry summarizes the most well-developed of these connections and introduces some of the major topics in the philosophy of risk. It consists of seven sections dealing with the definition of risk and with treatments of risk related to epistemology, the philosophy of science, the philosophy of technology, ethics, decision theory, and the philosophy of economics.