<p>Nearly half of the world’s wetlands are located in international river basins, highlighting the potential for cross-border governance and cooperation. Yet, little research exists that explores how states cooperate on wetlands and where this cooperation is present or lacking. Where wetlands cross borders, numerous and potentially divergent laws, policies, and conflicting priorities of multiple states influence their existence. Building on previous work, this global analysis assesses to what extent international freshwater agreements and institutions support wetlands in international river basins, with examples from various wetlands across the globe. Implementation of the 1971 Convention on Wetlands of International Importance especially as Waterfowl Habitat is reinforced by laws and policies at the basin, country, and local levels. Wetlands are mentioned in about 10% of international freshwater treaties which apply to wetlands in about 13% of the world’s international river basins. The results indicate that multiple levels of governance facilitate international cooperation on wetlands, but there is limited interaction between the levels and many gaps exist. Resolving these gaps and improving transboundary cooperation on wetlands is one way to work toward achieving international objectives on sustainability, water, climate, and biodiversity.</p>