Carbon leakage – the increase of greenhouse gas emissions in foreign jurisdictions following the introduction of domestic or regional climate mitigation measures – raises key questions in the climate change debate. This includes whether carbon leakage constitutes a threat to the environmental integrity of climate policies and, if so, how this could be mitigated. Through the use of four hypothetical models of international climate change regime, this article argues that international climate change law is a key factor in answering this two-part question. Firstly, the article demonstrates that the architecture of international climate change law affects whether carbon leakage can be considered as undermining the mitigation objective of climate policies. Secondly, it draws attention to the interaction – and potential tension – between carbon leakage prevention measures and international climate change law.