The Health and Environment Strategic Alliance (HESA) is an initiative established after the Libreville Conference on Health and Environment in Africa and the adoption of the Libreville Declaration in 2008. HESA is built around the idea that social and economic development cannot be achieved sustainably without addressing the root causes of ill health simultaneously with threats to ecosystems.

The purpose of HESA is to help coordinate action between these sectors and engage in country-level development planning processes, with the aim of protecting and promoting public health and ecosystem integrity. Managing the interlinkages between these sectors is an important means for achieving sustainable development and attainment of the United Nations Sustainable Development Goals (SDGs).