<p>Climate change profoundly affects forest structure, ecosystem functioning, and species distributions. As a Tertiary relict and a representative late-successional tree species, Korean pine (<i>Pinus koraiensis</i>) has undergone substantial range contraction due to overexploitation and is particularly sensitive to climate change. Using a more comprehensive and geographically representative set of occurrence records than previous studies, we applied an ensemble species distribution modelling (SDM) approach to project suitable habitats for Korean pine from the Last Glacial Maximum (c. 22,000 years ago) to future climate scenarios (2081–2100). We focused on the potential existence of high-latitude glacial refugia and the dynamics of suitable areas beyond the current natural range, aiming to infer the historical origins of its present distribution and to inform conservation planning. Our results suggest that central Honshu (Japan), the Baekdu-Daegan Mountain Range (originating from the Changbai Mountains), and the coastal region of Primorsky Krai in Russia may have served as long-term refugia for Korean pine. This study is, to our knowledge, the first to propose the coastal area of Primorsky Krai as a possible glacial refugium and further suggests that the current mainland distribution may have originated from remnant populations in the Baekdu-Daegan and potentially in the Russian coastal region. We also found that precipitation and the maximum temperature of the warmest month are the primary climatic factors limiting the species’ survival outside its natural range. Based on these findings, we recommend incorporating the identified long-term stable areas into core conservation networks, prioritising introduction trials in potentially suitable northern habitats, and dynamically adjusting protected area boundaries and management strategies to support the species’ climate adaptation.</p>