The Federation of South Arabia (FSA; Arabic: اتحاد الجنوب العربي Ittiḥād al-Janūb al-‘Arabī) was a federal state under British protection in what would become South Yemen. Its capital was Aden.

Originally formed on April 4, 1962 from 15 states of the Federation of Arab Emirates of the South. On January 18, 1963, the Royal Colony of Aden joined it. After the annexation of the Upper Aulaki Sultanate in June 1964, the federation included 17 states.

On July 23, 1962, negotiations began in London between the British Minister of Colonies, Duncan Sandys, and the ministers of the Federation of South Arabia and the Colony of Aden. The parties raised the issue of the constitutional status of Aden and the conditions for its entry into the federation. Numerous parties and organizations in Aden protested against these negotiations, declaring that the colonial ministers did not have the right to decide the fate of the population of Aden and that only the national government of Aden, created by general elections, would be competent to decide the question of a union with the federation. To achieve all this, it was necessary to eliminate its dependence on England. Representatives of the opposition, led by the Aden Trade Union Congress, said that any union concluded against the will of the people of Aden would be dissolved at the first opportunity. On the day the London negotiations began, a protest strike was declared in Aden. The Aden Trade Union Congress called for this strike, despite the fact that Aden had had a law prohibiting strikes since 1960, and violators were subject to imprisonment.

On August 16, 1962, negotiations ended with the signing of an agreement, according to which Aden, while remaining under British sovereignty, was to become part of the Federation of South Arabia on March 1, 1963. The agreement provided that the federation agreement, signed on February 11, 1959, will remain in force, and the new agreement will be only an addition to it. During these negotiations, agreement was also reached to introduce minor changes to the constitutional status of Aden once it became part of the federation.

In 1965, the British temporarily removed the government of the Federation of South Arabia and imposed direct colonial rule.

In 1966, the federation team took part in the Commonwealth Games in Kingston, Jamaica. The Federation was dissolved following independence along with the Protectorate of South Arabia and the formation of the People's Democratic Republic of Yemen on November 30, 1967.

Flag	Name	Established	Joined	Notes
	State of Aden	1963
	Alawi Sheikhdom	unknown
	Aqrabi Sheikhdom	1770
	Audhali Sultanate	18th century
	Emirate of Beihan	1680
	Dathina Sheikhdom	18th century
	Emirate of Dhala	early 19th century
	Fadhli Sultanate	17th century
	Haushabi Sultanate	18th century
	Sultanate of Lahej	1728	1872	formerly ruled over Aden
	Lower Aulaqi Sultanate	18th century
	Sultanate of Lower Yafa	ca. 1800
	Muflahi Sheikhdom	1850
	Sheikhdom of Shaib	18th century
	Upper Aulaqi Sheikhdom	18th century
	Upper Aulaqi Sultanate	18th century
	Wahidi Sultanate	1830		consisted originally of four sub-sultanates: Wahidi Balhaf, Wahidi Azzan, Wahidi Bir Ali, Wahidi Haban

State	Last Ruler	Deposed	House	Reign	Ref(s)
Alawi	Salih ibn Sayil	28 August 1967	Al Alawi	Last reigning Sheikh (1940–1967).
Aqrabi	Mahmud ibn Muhammad	28 August 1967	Al Aqrabi	Last reigning Sheikh (1957–1967).
Audhali	Salih ibn al-Husayn	17 September 1967	Al Audhali	Last reigning Sultan (1928–1967).
Lower Aulaqi	Nasir ibn Aidrus	29 November 1967	Al Awlaqi	Last reigning Sultan (1947–1967).
Upper Aulaqi	Awad ibn Salih	29 November 1967	Al Awlaqi	Last reigning Sultan (1935–1967).
Beihan	Saleh bin al-Husayn	28 August 1967	Al Habieli	Last reigning Emir (1935–1967).
Dhala	Shafaul ibn Ali Shaif	17 August 1967	Al Amiri	Last reigning Emir (1954–1967).
Fadhli	Nasir bin Abdullah	29 November 1967	Al Fadhli	Last reigning Sultan (1964–1967).
Haushabi	Faisal bin Surur	29 November 1967	Al Haushabi	Last reigning Sultan (1955–1967).
Lahej	Fadhl VI bin Ali	17 August 1967	Al Abdali	Last reigning Sultan (1958–1967).
Wahidi Balhaf	Ali ibn Muhammad	17 August 1967	Al Wahidi	Last governing Hakim (1967).
Wahidi Bir Ali	Alawi ibn Salih	29 November 1967		Last reigning Sultan (1955–1967).
Wahidi Haban	Husayn ibn Abdullah	29 November 1967		Last reigning Sultan (until 1967).
Lower Yafa	Mahmud ibn Aidrus	28 August 1967	Al Afifi	Last reigning Sultan (1954–1967).

• Hassan Ali Bayumi (18 January 1963 – 24 June 1963)
• Zayn Abdu Baharun (9 July 1963 – 23 January 1965)
• Abdul-Qawi Hassan Makkawi (7 March 1965 – 25 September 1965)
• Ali Musa al-Babakr (25 September 1965 – 30 August 1966)
• Salih al-Awadli (30 August 1966 – 30 November 1967)

• Sir Charles Johnston (18 January 1963 – 17 July 1963)
• Sir Kennedy Trevaskis (17 July 1963 – 21 December 1964)
• Sir Richard Turnbull (21 December 1964 – 22 May 1967)
• Sir Humphrey Trevelyan (22 May 1967 – 30 November 1967)

The Federation issued its own Adeni postage stamps from 1963 to 1966. Most of its issues were part of the omnibus issues common to all the Commonwealth territories, but it did issue its own definitive stamps on 1 April 1965. The set of 14 included 10 values, from 5 to 75 fils, each depicting the arms of the Federation in a single color, while the top four values (100 fils, 250 fils, 500 fils, and 1 dinar), featured the flag of the Federation.

The stamps referred to above are those listed in the Scott Standard Postage Stamp Catalog. A number of other stamps have also been issued and are listed in Stanley Gibbons and other widely used stamp catalogs. It is possible, or even likely, that some of the stamps of South Arabia were not issued primarily for postal use.

• United Nations Security Council Resolution 188

• Paul Dresch. A History of Modern Yemen. Cambridge, UK: Cambridge University Press, 2000.
• R.J. Gavin. Aden Under British Rule: 1839-1967. London: C. Hurst & Company, 1975.
• Tom Little. South Arabia: Arena of Conflict. London: Pall Mall Press, 1968.

• Media related to Federation of South Arabia at Wikimedia Commons
• South Arabia and Yemen, 1945-1995

15°19′48″N 48°04′34″E / 15.330°N 48.076°E / 15.330; 48.076