The IANAS Manaus Letter was presented at the IANAS-ABC Science By and For the Amazon event, held in August 2-3, at the National Institute for Amazonian Research (INPA) in Brazil. Presidents and Representatives from IANAS Member Academies as well as scientists and policy makers from Amazonian countries participated in the making of this document. The main goal of the IANAS Manaus Letter, that is available in English, Spanish and Portuguese, is to support regional academies for Amazonian countries to work together and bring attention to the Amazon biome, focusing in four main axes: 1) Considering the Amazon as a regional entity of the Earth system. 2) The human presence and socio-cultural diversity in the Amazon. 3) Socio-ecological transformations. 4) The search for solutions for the sustainable development of the Amazon. We strongly encourage our Member Academies and partner organizations to disseminate this letter within your network.