Reducing child poverty has the potential to improve incomes and health for both present and future generations and, thereby, break the inter generational transmission of poverty that affects lives and livelihoods. For several decades evidence has shown the considerable impact of social protection programmes on human development outcomes for children. However, the impact varies across countries and depends critically on context, including availability of other services, as well as design and implementation of programmes. To maximize the impact on children it is essential to take a child-lens to the design and implementation of social protection systems, which comprise programmes to address risks across the life-cycle. This article will outline how child-sensitive social protection programmes impact on children and assess the extent and coverage in developing countries. The article will then outline principles of child-sensitive social protection and key aspects to improve impact on children, using examples from a number of social protection programmes globally. Lastly, the article will outline lessons on what works for children in social protection and will provide policy recommendations for policymakers and other actors, including civil society, that support social protection systems.