A growing literature in economics has studied how fairness considerations shape human behavior. This review analyses the key theoretical and empirical contributions spanning the last four decades, along with influential related work in normative economics. It argues that the fairness motive is essential for understanding human behavior in a wide range of settings, such as markets, bargaining, and redistributive situations. It moves on to a discussion of the large heterogeneity in what people view as fair and the importance people attach to fairness, displaying how a concern for fairness develops in childhood and manifests itself in the brain. This research review will be a valuable tool for those interested in the fascinating field of the economics of fairness.