While increasing temperatures in Ireland are projected to occur in all seasons and time periods, it is likely that projected changes in the seasonal and spatial distribution of rain will present a much greater challenge, particularly during the summer months in the south and east of the country. Reductions in summer precipitation, leading to significant decreases in water availability and quality will result in increased competition between municipal, agricultural, and commercial interests, including tourism. Decreases in summer precipitation, together with increased evaporative losses are also likely to affect terrestrial ecosystems, particularly water dependant systems such as turloughs and fens. Changes in seasonal water levels and the occurrence of extreme high and low flow events will directly impact on river navigability, cultural heritage, and the plant and animal communities of the riparian zone. Inland waterways also provide an important resource for potable water extraction and effluent removal, in addition to providing a tourism and recreational resource. Climate change will also result in changes in sea level, wave energy and storm surges with consequent impacts on the coastal environment, particularly for coastal heritage. These impacts are likely to be further exacerbated due to ‘non-climate’ pressures arising from increasing population and development within the coastal zone. In order to determine the likely impacts of climate change on inland waterways and the coastal environment in Ireland, this chapter will present a review of recent research as it applies to impacts in these areas in Ireland.