Nature based tourism industry is undoubtedly not immune to climatic changes. The climatic changes are due to natural causes but others are attributed to human activities. The purpose of the study was to determine the effects of climate change on tourism sustainability in Maasai Mara National Game Reserve (MMNGR), Kenya. The study adopts explanatory research design. The sample size was 507 respondents comprising of 399 households, 90 tourists and 18 experts selected by simple random sampling, convenience sampling and snowball sampling respectively. Structured questionnaires collected data from the host community which was analyzed using Pearson product moment of correlation, linear and multiple regressions. Data analyses were done through quantitative techniques of descriptive and inferential statistics with the aid of SPSS V.23. Results indicated that there is a positive significant relationship between climate change and tourism sustainability in MMNGR (β1=0.818 and p<0.05). Despite modest adaptive capacity to climate change effects, the study raises urgent interventions for the tourism industry stakeholders on rainfall and temperature variations that positively contribute to influence the decline in wildlife populations that impedes sustainability of tourism. Future research could consider use of other climate change indicators other than rainfall and temperature in assessing climate change impacts.