Abstract: Climate change have significant impacts on Nigeria’s freshwater and marine aquatic systems and hence on the country’s fisheries and aquaculture. Fisheries and aquaculture are highly vulnerable to changes in weather pattern and the impacts which could be negative or positive, vary from the coastal areas to the drier northern parts of the country. Elevated water temperatures affect fish physiological processes, thereby affecting spawning, survival of the juveniles, recruit into the exploitable phase of population, population size, production and yield. The impacts of increased flooding of the freshwater bodies will be negative through erosion of watershed, destruction of fish feeding and breeding habitats, decrease in primary productivity and alteration of the normal resilience of the aquatic systems, or positive in expansion of aquatic habitats for primary and fish productions especially during the dry season. Drought exacerbate draw down of the lakes and reservoirs and insufficient flow in the river basins for spawning and primary production thereby affecting fish production. Rise in the water level of the Atlantic ocean lead to intrusion of more salty water into the river delta areas and inundation of the coastal low-lying areas, thus affecting distribution of both the freshwater and marine fishes as a result of changes in the physical and chemical properties of the waters. The impacts ultimately affect fish population, production and supply, thereby affecting the livelihoods of over 26 million people engaged in the primary and secondary sectors of the fisheries industry, as well as food security of the country. The adaptation and mitigation strategies are based on the peculiar characteristics and interactions of fisheries and aquaculture within the framework of feasible policy instruments. Strategies and policy measures need to be evolved to combat the observable and projected impacts of climate change on fisheries and aquaculture in order to protect the livelihoods of the fishing communities and food security.