The Bright Star are now members of the continental football governing body and Sepp Blatter-led Fifa, 10 months after gaining independence
Delegates attending the annual congress of Fifa in Hungary gave the African nation the green light to become the 209th member.
The induction means South Sudan can now participate in the 2015 Africa Cup of Nations and 2018 World Cup qualifiers.
They became members of the Confederation of African Football (Caf) in February after having gained independence in July, 2011.
“We are still suffering from war, so we promise that we will develop football to fight against war, hunger and poverty,” Oliver Mori Benjamin, South Sudan FA president told delegates after gaining their nods.
"I want to assure you that we are going to follow the statutes and regulations of Fifa and obey the law of our good game.”
He added, "I want to assure you that in my state in South Sudan, Abyei, we are still in a war zone but I promise in a few days, we are going to raise the flag of Fifa in Abyei for the good of our people."
Mr. Benjamin also expressed his gratitude to Caf president, Issa Hayatou, for accepting them in the continent’s football fraternity.
"I want to thank the president of Caf for our admission to Caf in Gabon [in February] - we are really so happy and satisfied under your leadership in Africa.
"I would like to thank the Sudan national association for football for your fruitful co-operation and for your acceptance of our membership in Caf," he said.