Standing in the way of sustainable business efforts is the belief that corporate fiduciaries must work to maximize shareholder wealth at all costs. American corporate law in fact imposes no such obligation, yet shareholder wealth maximization remains a powerful social norm. This chapter explores the history of the shareholder primacy norm, tracing the idea from its inception, to its famous articulation in the classic case of Dodge v. Ford, through the influence of the law and economics movement and the rise of financialism at the end of the last century. The chapter then examines the current debate over shareholder primacy, sustainability, and corporate social responsibility, arguing that shareholder primacy has peaked in the United States and is meeting resistance internationally. A new norm of enlightened stakeholderism, I argue, is on the rise, pursuant to which firms aim to be not just profitable but environmentally and socially responsible, as well.