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The El Niño-Southern Oscillation (ENSO) is the world’s largest source of interannual climate variability, having near-global impacts on temperature and precipitation, including extreme events. This thesis aims to understand how ENSO’s remote impacts on climate, known as teleconnections, are projected to change in the future due to climate change. We first investigate the projected changes in ENSO’s teleconnections over global land areas in the Coupled Model Intercomparison Project phase five (CMIP5) models. We show that the CMIP5 models project a robust increase in the areal extent of ENSO’s temperature and precipitation teleconnections in the high-emission future simulations. This projected change is robust across the ensemble when (i) a significant majority of models agree on the location of ENSO’s impacts, and (ii) the models are assessed individually. Our results also suggest that this projected change is associated with changes in ENSO-driven precipitation in the tropical Pacific. Second, we investigate if the CMIP5 models project robust changes in the magnitude of ENSO’s teleconnections, focusing on regional scale impacts over land during composited El Niño and La Niña events. We show that the CMIP5 models do not agree on robust projected changes in the strength of ENSO’s teleconnections for the majority of regions. Using a large ensemble of simulations from one coupled-model, we show that this lack of agreement is at least partly related to internal variability. However, the CMIP5 ensemble projects a robust amplification of the historical teleconnections for some regions. Finally, we assess how the projected changes in atmospheric processes lead to the simulated changes in ENSO’s teleconnections. We analyse an idealised atmosphere-only model experiment and focus on ENSO’s regional teleconnections in South America, where robust changes are projected to occur. We show that the model simulates an increase in ENSO-driven precipitation in the tropical Pacific that results in changes in large-scale atmospheric circulation in the tropics and extra-tropics. We show that the projected changes in ENSO’s South American teleconnections are related to the changes in circulation. We further show that simulated changes in the land-atmosphere interactions as a result of the modified teleconnections further enhance ENSO’s impacts.