Although ethical critiques of markets are longstanding, modern academic debates about the “moral limits of markets” (MLM) tend to be fairly limited in scope. These disputes center, not on the dangers of markets per se, but on the dangers of exchanging particular items and activities through the marketplace. Proponents of MLM theories thus do not want to eliminate markets entirely, but instead seek to identify the moral and ethical boundaries of the marketplace by considering which goods and services are inappropriate for market trading. This chapter summarizes and categorizes some of the more important arguments within this debate, with a focus on recent research, controversies, and applications. The goal is to provide an overview of these debates, highlighting some of the topics that have generated robust discussion, particularly when relatively recent empirical or theoretical work may shed new light on a topic. Specifically, I focus on crowding out, corruption, leaving a space for altruism, equality, and a trio of related debates regarding paternalism (coercion, unjust inducement, and exploitation).