Recent debate on whether the climatic niche of species is conserved or not in a context of climate change has generally focused either solely on invasive species or on a relatively limited number of native species. However, invasive species may not be optimal for assessing the likelihood of niche conservatism because the time since geographical separation is usually short. Our results are based on a large sample size of populations of 389 terrestrial vascular plant species, with various biogeographic, ecological and biological features, occurring in both the European Alps and Fennoscandia but originating from different colonization events that have taken place since the Last Glacial Maximum (LGM). Using two complementary approaches, we first tested for a region effect on each species’ climatic niche and then quantified niche overlap and niche shifts within a bi-dimensional climatic space. We found only 59 species (15%) for which the climatic niche is different between the two regions. Observed niche overlap between distant populations of the same species was greater (menSE: 0.420.006) than expected under the null assumption that the climatic niche of a given species is identical in both regions (menSE: 0.280.01). We found the highest niche overlap values for specialist species like Arctic-alpine plants and for plant species benefiting from either low dispersal constraints due to habitat fragmentation or high dispersal abilities. Although these findings suggest a weak regional imprint of the LGM on the climatic niche of species, we also found that the climatic niche was, on average, larger and located towards warmer and drier conditions in the Alps than in Fennoscandia, suggesting more opportunity for species in the Alps to fill their fundamental niche over time and to adapt to local conditions, consistent with the higher intraspecific genetic diversity in the Alps.