Prochlorococcus, Synechococcus, and picoeukaryotic phytoplankton dominate oligotrophic oceans, contributing at least 10% of global primary productivity, are central to global biogeochemical cycles and, thus, there is growing interest to include them in Earth System Models. However, global datasets of these groups are sparse in time and space representing a strong limitation to validate biogeochemical models. Here, we provide a global compilation of in situ observations along with ancillary environmental variables, a global climatology, and a projected global abundance in future climate scenarios aimed to overcome these limitations.