This chapter summarises the main contributions of Jean Tirole to academic research in economics and other social sciences. Jean received the Alfred Nobel Memorial Prize in 2014 for his work on “how to understand and regulate industries with a few powerful firms”. But he has also contributed to many other domains of economic research, including game theory, contract theory, banking regulation and corporate finance. More recently, Jean has shown how contract theory and game theory can be applied to psychology. He is currently exploring a broad research agenda on how technology is influencing the way society functions.