Ecosystem services provide benefits to humans, and those services are strongly linked to morphological traits in species and the functional diversity of communities. Pollination services are important for agricultural productivity and wild plant support, and bumblebees serve as a key pollinator group in temperate and boreal ecosystems. Bumblebees are facing threats such as changes to land-use and climate that result in shifts to geographic ranges, physiology, and morphology, which in turn decrease functional diversity. Here, to conserve and manage areas important for functional diversity of pollinators in Japan, we predicted and mapped functional diversity of bumblebees using species distribution models and kernel density hypervolumes. We examined differences in patterns of functional diversity and species richness with linear models. We also calculated functional redundancy for each community based on extinction simulations to identify areas vulnerable to loss of ecosystem function, and additionally investigated species’ contributions to the total functional diversity across Japan. Species richness and functional diversity was highest in central Honshu and low elevation areas across Hokkaido. Further, richness was positively correlated with functional diversity, but the degree of correlation differed between Honshu and Hokkaido. Most communities had lower functional diversity than expected by chance, showing functional underdispersion and redundancy. Extinction simulations showed high vulnerability to functional diversity losses mainly in Hokkaido, with high functional resistance in central Honshu, and a significant negative relationship with species richness. These results demonstrate that pollinator functional diversity and relationships with species richness can have broad geographical variation, highlighting the need for more studies across different biogeographic regions. This workflow can produce pollinator functional diversity and vulnerability maps for estimating ecosystem service provisions at the regional scale, and next steps can investigate impacts of climate and land-use change on these services.