Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopia to the southeast, and South Sudan to the south. Sudan has a population of 51.8 million people as of 2025 and occupies 1,886,068 square kilometres, making it Africa's third-largest country by area. Sudan's capital and most populous city is Khartoum.