Egypt

Egypt ranks fourth with 107.2 million people, 95% of whom live within 20 kilometers of the Nile River—a density that creates one of the world’s most concentrated populations. Its growth rate has slowed to 1.7% annually, below the sub-Saharan average of 2.7%, leading to a demographic slowdown compared to Nigeria’s 2.4% and Ethiopia’s 2.5%. Cairo alone houses 21 million residents, making it Africa’s largest city and a pressure point for housing and water. Egypt’s fertility rate of 3.3 births per woman is the lowest among the top four, signaling a gradual aging trend, though its median age of 24.1 years remains younger than #1 Nigeria’s 18.1. The country’s GDP per capita of $4,000 tops the list, boosting economic output per person.