Saint Pierre and Miquelon: none (territorial collectivity of France; has been under French control since 1763)
Saint Vincent and the Grenadines:
27 October 1979 (from UK)
Samoa:
1 January 1962 (from New Zealand-administered UN trusteeship)
San Marino:
3 September 301
Sao Tome and Principe:
12 July 1975 (from Portugal)
Saudi Arabia:
23 September 1932 (Unification of the Kingdom)
Senegal:
4 April 1960 (from France); complete independence was
achieved upon dissolution of federation with Mali on 20 August 1960
Seychelles:
29 June 1976 (from UK)
Sierra Leone:
27 April 1961 (from UK)
Singapore:
9 August 1965 (from Malaysia)