The sustainability of ski tourism is directly related to the prevailing climatic conditions. This study investigates the impact of climate change on the sector of ski tourism in Greece. For this purpose, the current situation is assessed and the changes in underlying climatic parameters (temperature, snow cover, snow depth) are examined on the basis of a selected climatic scenario (RCP 4.5) for ski tourism in Greece in general, but also for the specific case of the Parnassos ski resort (PSR). The results refer to the period 2051–2060 compared to 1971–1980 and show a clear increase in temperature and a considerable decrease in snow cover and snowfall throughout the Greek territory, as well as in the special case of PSR. The results for specific snow indicators (duration of the snow season, number of days with an amount of at least 100 and 120 kg m−2 of natural, groomed, or managed snow, and potential snowmaking hours for wet bulb temperature lower than −2 and −5 °C) from climate projections for the 1971–2099 period further highlight the risk for mountain tourism in Greece. Decreasing trends for all examined parameters are found for the RCP 4.5 and the RCP 8.5 scenarios. In light of these findings, necessary adaptation measures against climate change are proposed in order to maintain the viability of the ski tourism sector in Greece.