Marmosini is the most speciose marsupial tribe of Colombia with 19 species, but basic aspects of their biology remains unknown, including information on their distribution and conservation. The main objectives of this work were to study Marmosini species richness, potential distribution, and conservation throughout Colombia. To achieve this, we generated ecological niche models in a reproducible framework, in which we tested the use of different combinations of environmental data (WorldClim, ENVIREM, modified soil adjusted vegetation index (MSAVI)), modeling areas, cross-validation methods, and evaluation metrics using our data from Colombian Marmosini. Models for each species were explored for shared environmental and conservation patterns across all species, and using ecological and human-related (e.g., protected areas) data specific to Colombia. We found models that included WorldClim, ENVIREM and MSAVI variables, and modeling areas based on ecoregions performed better with our sample. Precipitation variables were more important for 8 species, while temperature variables were more important in 5 species, and topographic variables were important in the remaining species. Marmosini species’ potential distribution covers 91% of the country's continental area, and the protected area for any species of this group ranges between 5.4% and 29% of their modeled distribution. Most protected areas classified as strict-conservation presented small areas of high human pressure, while other categories (e.g., managed resources) presented large areas of high human pressure. We found that high potential species richness of Marmosini occurs at mid-elevations on the Andes with an upper elevation limit of maximum richness at ~ 2000 m. These species distributions are poorly covered by the natural protected areas of Colombia. We identified the transition zone between the Eastern Andes and Amazonian regions as a key area for conservation efforts in these little known marsupials.