Golden lion tamarins are endemic to the Atlantic coastal forests of Brazil. They are found within the state of Rio de Janeiro and a small area in the nearby state of Espírito Santo. Their natural habitat consists of dense lowland rainforests, both primary and secondary, located within the Serra do Mar mountain range. These rainforests are characterized by tall trees, dense understory vegetation, and a high diversity of plant species. Golden lion tamarins prefer areas with abundant fruiting trees, as fruits make up a large portion of their diet. They are found at elevations ranging from sea level up to 1,000 meters (3,280 feet).
The Atlantic coastal forests of Brazil, where golden lion tamarins reside, are considered a biodiversity hotspot due to their exceptional levels of species richness and endemism. However, these forests are under significant threat from deforestation, fragmentation, and other human activities. The loss and degradation of their habitat have been major contributing factors to the decline of golden lion tamarins in the wild. Conservation efforts and habitat restoration initiatives have been implemented to protect the remaining populations and ensure the long-term survival of this critically endangered species.