This paper explores the intersection of transnational law with contemporary corporate governance laws and principles. Transnational law, it must be said, is a far from settled concept. There is uncertainty as to what the term actually means, and how it differs from other concepts, such as national legal ordering or global law. For early theorists, the essence of transnational law was whether it regulated conduct or events that crossed national boundaries. More recent scholarship, however, has focused not on what is being regulated, but rather on how laws and norms are transmitted between supranational and local levels.Corporate governance, with its complex array of public and private actors, fits naturally within the modern conception of transnational law as a species of law that “can no longer be viewed through a purely national lens”. Financial markets today are global and interconnected and events, such as the 2007-2009 global financial crisis and the current COVID-19 crisis, exemplify the risk of contagion across those markets.Not only can corporate governance problems transcend national boundaries, so too can their solutions, which often involve regulatory efforts that operate at a transnational level. In this environment, the corporation has taken on a greater societal role. Indeed, according to The British Academy’s influential Future of the Corporation project, the main purpose of business today is “to solve the problems of people and planet profitably”.This paper explores, from a transnational perspective, the transmission of laws and norms that are designed to constrain directors’ conduct and enhance corporate accountability. It focuses on two key examples of such accountability mechanisms —fiduciary duties and corporate codes.The paper begins with a comparative and historical examination of directors’ fiduciary duties in the United States, the United Kingdom and Australia, analyzing the extent to which the transfer of fiduciary law to these common law jurisdictions has resulted in a unified approach to directors’ duties, as is often assumed by studies such as the law matters hypothesis. The paper then moves on to discuss the modern phenomenon of codes, such as corporate governance codes and shareholder stewardship codes. Corporate codes originated in the United Kingdom in the early 1990s, but have subsequently spread throughout the world. The paper explores the global transmission of these codes, which constitute powerful “norm creators”. The rise of corporate codes epitomizes the fact that transnational legal ordering occurs “multi-directionally and recursively up from and down to the national and local levels”. It also demonstrates the importance of “who writes the rules”, because this can affect the substance of those rules and result in significant divergence between national codes.The paper assesses these various developments against the backdrop of convergence and path dependence theories in corporate governance.