The rapid and widespread establishment of domestic environmental courts and tribunals raises important questions regarding their implications for international environmental law and global environmental governance. I use an interdisciplinary, multi-method approach to consider the capacity of domestic environmental courts to identify and apply norms and principles of international environmental law in domestic opinions. I first review existing literature, identifying jurisdiction, judicial discretion, and a court's position in a legal system as key institutional determinants of this capacity. I then develop a typology of domestic environmental courts and tribunals, which suggests that, all else being equal, a court with national geographic jurisdiction that also enjoys attributes of broad subject-matter jurisdiction and discretion may be expected to be best equipped to implement norms and principles of international environmental law. Next, I integrate existing assessments of environmental court presence with original outreach and web research to identify all countries which possess environmental courts, and assess a subset of eight existing national-level institutions. The analysis of this subset highlights the diversity of institutional models that can incorporate theorized best practices. Based on these findings, I draw several theoretical conclusions: specifically (i) the relevance of environmental court research to individual- and institutional-level analysis in transnational and international environmental law, (ii) the need for further legal-institutional analysis in global environmental governance scholarship, and (iii) the opportunity for further interdisciplinary analysis of the role of domestic courts in environmental governance.