Many animal and environmental activists think of international trade law as a block to the achievement of their goals and perceive the World Trade Organization (WTO) as a threat to animals. Yet, the first legal decision of an international tribunal to devote careful, sustained attention to animal welfare issues comes from the WTO, in the EC – Seal Products decision. This article argues that international trade law is currently an important, although under-acknowledged, locus for the development of global norms concerning the protection of animals, and that animal conservation and animal welfare can be seen as aspects of a single overarching principle of animal protection. International trade law contributes to animal protection in two ways. Firstly, WTO jurisprudence has recognized animal protection as a legitimate basis for invoking exceptions to trade rules (as in EC – Seal Products). Secondly, international trade negotiations enhance cooperation on the implementation and enforcement of existing conservation obligations (as in the new Trans-Pacific Partnership’s Environment Chapter).