This book chapter proposes a typology of the different ways that domestic courts may use foreign law — as binding law, as a nonbinding norm, as an interpretive aid, as a basis for functional comparison, and as factual information — and it explores the implications of these different uses for judicial internalization of external norms. The chapter argues that domestic courts play a key role in transnational processes of norm internalization and diffusion, and it draws on political science scholarship to develop hypotheses about how different uses of foreign law by domestic courts affect these processes.