Approximately 17% of the world’s 7.5 billion people live in Africa, and by 2065, the continent’s population will comprise 28% of the world’s population. Roughly 60% of the African population is less than 25 years old (compared with 41% globally), and on average, an African woman expects to have at least four children during her lifetime, compared to less than three children for the rest of the world. High fertility and falling child mortality rates have led to high annual population growth rates in Africa (on average 2.5% compared to 1.1% for the world). The East African Community (EAC), is a regional intergovernmental partnership between six countries (Burundi, Kenya, Rwanda, South Sudan, Uganda, and the United Republic of Tanzania), originally conceived in 1967 by three founder states (Kenya, Uganda, and Tanzania), and formally established in 2000 by a treaty. The pillars of integration, which are at various stages of implementation, include customs union, common market, monetary union, and ultimately political federation. The four EAC countries (Kenya, Rwanda, Tanzania, and Uganda), which are the focus of this briefing note, have a combined population of more than 150 million, with Rwanda being the smallest in terms of population size. Like the rest of Africa, the EAC is experiencing demographic changes which are affecting not just the size, but also the age-structure and the region’s social and economic progress.