Understanding the long-term stability of suitable habitats is essential for conserving threatened species, particularly in the face of climate change. This study utilized ecological niche modeling (ENM) based on the maximum entropy to understand the potential impacts of climate change on the distribution of two endangered Castanopsis species in Indonesia, C. argentea and C. tungurrut. The objectives were to identify the key climatic drivers, map suitable habitat across past (Last Glacial Maximum [LGM] and Mid-Holocene [MH]), present, and future (2041-2070 under SSP126 and SSP585) periods, and identify potential climate refugia. Occurrence data were obtained from GBIF, herbarium records, articles, and field surveys. Initially, ten climate variables from CHELSA were used for model construction, later refined to four key predictors for each species. Precipitation during the driest periods emerged as the primary determinant of species distributions, highlighting vulnerability to drought. Historical simulations suggest broader suitable ranges during past climatic periods, except for C. tungurrut in the MH. Future projections suggest habitat contraction under all scenarios; however, potential stable habitats and climate refugia persist, particularly in the Sumatran highlands (Bukit Barisan Mountains), Java’s mountain ranges, and scattered parts of Kalimantan, despite localized habitat fragmentation. The identification of highly suitable but unrecorded areas, particularly in Aceh, eastern Java, and central Kalimantan, emphasizes the need for further field surveys to confirm potential populations. To support these species conservation, this study recommends strengthening management effectiveness within protected areas, enhancing community-based forest conservation, encouraging sustainable land-use in surrounding landscapes, and replanting programs in degraded but their suitable habitats.