| Country | Constitution |
| Pakistan | 12 April 1973; suspended 5 July 1977, restored 30 December 1985; suspended 15 October 1999, restored in stages in 2002; amended 31 December 2003; suspended 3 November 2007; restored on 15 December 2007 |
| Palau | 1 January 1981 |
| Panama | 11 October 1972; major reforms adopted 1978, 1983, 1994, and 2004 |
| Papua New Guinea | 16 September 1975 |
| Paracel Islands | void |
| Paraguay | promulgated 20 June 1992 |
| Peru | 29 December 1993 |
| Philippines | 2 February 1987, effective 11 February 1987 |
| Pitcairn Islands | 30 November 1838; reformed 1904 with additional reforms in 1940; further refined by the Local Government Ordinance of 1964 |
| Poland | adopted by the National Assembly 2 April 1997; passed by national referendum 25 May 1997; effective 17 October 1997 |
| Portugal | adopted 2 April 1976; note - subsequent revisions of the Constitution placed the military under strict civilian control, trimmed the powers of the president, and laid the groundwork for a stable, pluralistic liberal democracy; as well, they allowed for the privatization of nationalized firms and the government-owned communications media |
| Puerto Rico | ratified 3 March 1952; approved by US Congress 3 July 1952; effective 25 July 1952 |
| Qatar | ratified by public referendum on 29 April 2003, endorsed by the amir on 8 June 2004, effective on 9 June 2005 |
| Romania | 8 December 1991; revision effective 29 October 2003 |
| Russia | adopted 12 December 1993 |
| Rwanda | new constitution passed by referendum 26 May 2003 |
| Saint Barthelemy | 4 October 1958 (French Constitution) |
| Saint Helena | 1 January 1989 |
| Saint Kitts and Nevis | 19 September 1983 |
| Saint Lucia | 22 February 1979 |
| Saint Martin | 4 October 1958 (French Constitution) |
| Saint Pierre and Miquelon | 4 October 1958 (French Constitution) |
| Saint Vincent and the Grenadines | 27 October 1979 |
| Samoa | 1 January 1962 |
| San Marino | 8 October 1600; electoral law of 1926 serves some of the functions of a constitution |
| Sao Tome and Principe | approved March 1990, effective 10 September 1990 |
| Saudi Arabia | governed according to Islamic law; the Basic Law that articulates the government's rights and responsibilities was promulgated by royal decree in 1992 |
| Senegal | adopted 7 January 2001 |
| Serbia | adopted 8 November 2006; effective 10 November 2006 |
| Seychelles | 18 June 1993 |
| Sierra Leone | 1 October 1991; subsequently amended several times |
| Singapore | 3 June 1959; amended 1965 (based on preindependence State of Singapore Constitution) |
| Slovakia | ratified 1 September 1992, effective 1 January 1993; changed in September 1998 to allow direct election of the president; amended February 2001 to allow Slovakia to apply for NATO and EU membership |
| Slovenia | adopted 23 December 1991 |
| Solomon Islands | 7 July 1978 |
| Somalia | 25 August 1979, presidential approval 23 September 1979 note: the formation of transitional governing institutions, known as the Transitional Federal Government, is currently ongoing |
| South Africa | 10 December 1996; this new constitution was certified by the Constitutional Court on 4 December 1996, was signed by then President MANDELA on 10 December 1996, and entered into effect on 4 February 1997 |
| South Georgia and the South Sandwich Islands | void |
| Southern Ocean | void |