South Sudan (), officially known as the Republic of South Sudan, is a landlocked country in Central Africa. It is bordered by Ethiopia, Sudan, Central African Republic, Democratic Republic of the Congo, Uganda and Kenya. Its population was estimated as 12,778,250 in 2019. Juba is the capital and largest city. The nation is sometimes informally referred to as the Nilotic Republic (as the supposed place of origin of the Nilotic peoples).It gained independence from Sudan in 2011, making it the most recent sovereign state or country with widespread recognition as of 2022. It includes the vast swamp region of the Sudd, formed by the White Nile and known locally as the Bahr al Jabal, meaning "Mountain River". Sudan was occupied by Egypt under the Muhammad Ali dynasty and was governed as an Anglo-Egyptian condominium until Sudanese independence in 1956. Following the First Sudanese Civil War, the Southern Sudan Autonomous Region was formed in 1972 and lasted until 1983. A second Sudanese civil war soon broke out in 1983 and ended in 2005 with the Comprehensive Peace Agreement. Later that year, southern autonomy was restored when an Autonomous Government of Southern Sudan was formed. South Sudan became an independent state on 9 July 2011, following 98.83% support for independence in a January 2011 referendum. It has suffered ethnic violence and endured a civil war characterised by rampant human rights abuses, including various ethnic massacres and killings of journalists by various parties to the conflict from December 2013 until February 2020, when competing combat leaders Salva Kiir Mayardit and Riek Machar struck a unity deal and formed a coalition government, paving the way for refugees to return home.The South Sudanese population is composed mostly of Nilotic peoples, and it is demographically among the youngest nations in the world, with roughly half under 18 years old. The majority of inhabitants adhere to Christianity or various Indigenous faiths. The country is a member of the United Nations, the African Union, the East African Community, and the Intergovernmental Authority on Development.

United Nations Security Council Resolution 1999 was adopted without a vote on 13 July 2011 after examining the application of the Republic of South Sudan for membership into the United Nations. The Council recommended to the General Assembly that South Sudan be admitted.The resolution was adopted following a request from South Sudan President Salva Kiir. South Sudan became the 193rd member of the United Nations.