The GEF has 186 member countries. In the Instrument, GEF member countries are referred to as participants. In general terms there are developed and developing participants in the GEF. They are represented on the GEF Council by 32 constituencies (14 for developed countries, 16 for developing countries, and 2 for economies in transition) each one having a Council member and an alternate Council member. Representative of all member countries meet every four years during the GEF Assembly.
| Participants | Date of Participation |
| A | |
| Afghanistan | 04/07/1994 |
| Albania | 05/06/1994 |
| Algeria | 05/13/1994 |
| Angola | 10/29/2009 |
| Antigua & Barbuda | 03/29/1994 |
| Argentina | 05/12/1994 |
| Armenia | 06/16/1994 |
| Australia | 06/27/1994 |
| Austria | 06/21/1994 |
| Azerbaijan | 07/24/1995 |
| B | |
| Bahamas | 04/19/1994 |
| Bahrain | 03/11/2020 |
| Bangladesh | 06/22/1994 |
| Barbados | 05/13/1994 |
| Belarus | 03/30/1994 |
| Belgium | 01/30/1995 |
| Belize | 04/29/1994 |
| Benin | 06/29/1994 |
| Bhutan | 12/12/1995 |
| Bolivia | 06/17/1994 |
| Bosnia and Herzegovina | 10/29/2001 |
| Botswana | 07/12/1994 |
| Brazil | 06/13/1994 |
| Bulgaria | 03/22/1994 |
| Burkina Faso | 08/24/1994 |
| Burundi | 03/30/1998 |
| C | |
| Cambodia | 01/31/1995 |
| Cameroon | 10/31/1994 |
| Canada | 07/06/1994 |
| Cabo Verde | 07/18/1994 |
| Central African Republic | 03/23/1995 |
| Chad | 07/27/1994 |
| Chile | 07/01/1994 |
| China | 05/16/1994 |
| Colombia | 06/28/1994 |
| Comoros | 09/05/1995 |
| Congo, Dem. Republic of | 02/06/1997 |
| Congo, Republic of | 09/22/1995 |
| Cook Islands | 05/06/1994 |
| Costa Rica | 05/19/1994 |
| Côte d'Ivoire | 06/24/1994 |
| Croatia, Republic of | 03/04/1994 |
| Cuba | 04/04/1994 |
| Czechia | 06/30/1994 |
| D | |
| Denmark | 06/09/1994 |
| Djibouti | 05/24/1994 |
| Dominica | 06/08/1994 |
| Dominican Republic | 04/21/1994 |
| E | |
| Ecuador | 06/23/1994 |
| Egypt | 06/08/1994 |
| El Salvador | 05/20/1994 |
| Equatorial Guinea | 06/12/2003 |
| Eritrea | 12/27/1995 |
| Estonia | 05/12/1994 |
| Eswatini | 5/16/1994 |
| Ethiopia | 10/27/1994 |
| F | |
| Fiji | 05/10/1994 |
| Finland | 06/09/1994 |
| France | 06/20/1994 |
| G | |
| Gabon | 03/20/1998 |
| Gambia | 08/16/1994 |
| Georgia | 07/08/1994 |
| Germany | 06/23/1994 |
| Ghana | 01/16/1997 |
| Greece | 05/11/1994 |
| Grenada | 04/20/1994 |
| Guatemala | 05/20/1994 |
| Guinea | 10/17/1994 |
| Guinea - Bissau | 05/02/1995 |
| Guyana | 05/12/1994 |
| H | |
| Haiti | 05/10/1994 |
| Honduras | 09/06/1994 |
| Hungary | 06/22/1994 |
| I | |
| India | 05/12/1994 |
| Indonesia | 06/29/1994 |
| Iran (I.R.) | 05/25/1994 |
| Iraq | 02/03/2010 |
| Ireland | 06/14/1994 |
| Israel | 03/19/1995 |
| Italy | 06/28/1994 |
| J | |
| Jamaica | 06/29/1994 |
| Japan | 06/27/1994 |
| Jordan | 05/10/1994 |
| K | |
| Kazakhstan | 03/30/1998 |
| Kenya | 05/25/1994 |
| Kiribati | 05/10/1994 |
| Korea (D.P.R.) | 05/06/1994 |
| Korea (Rep.) | 05/03/1994 |
| Kosovo | 03/11/2010 |
| Kuwait | 06/05/2010 |
| Kyrgyzstan | 01/09/1997 |
| L | |
| Lao (P.D.R.) | 08/02/1994 |
| Latvia | 06/27/1994 |
| Lebanon | 07/21/1994 |
| Lesotho | 06/29/1994 |
| Liberia | 12/05/2000 |
| Libya | 12/13/1994 |
| Lithuania | 05/13/1994 |
| Luxembourg | 04/28/1995 |
| M | |
| Madagascar | 07/14/1994 |
| Malawi | 02/23/1996 |
| Malaysia | 05/04/1994 |
| Maldives | 08/25/1994 |
| Mali | 07/04/1994 |
| Malta | 07/27/1994 |
| Marshall Islands | 04/15/1994 |
| Mauritania | 05/08/1994 |
| Mauritius | 07/04/1994 |
| Mexico | 05/17/1994 |
| Micronesia (F.S.) | 04/26/1994 |
| Moldova | 10/27/1995 |
| Mongolia | 04/14/1994 |
| Montenegro | 08/25/2006 |
| Morocco | 06/29/1994 |
| Mozambique | 12/27/1995 |
| Myanmar | 05/13/1994 |
| N | |
| Namibia | 04/30/2001 |
| Nauru | 05/05/1994 |
| Nepal | 08/10/1994 |
| Netherlands | 06/20/1994 |
| New Zealand | 05/18/1994 |
| Nicaragua | 05/19/1994 |
| Niger | 08/23/1994 |
| Nigeria | 07/12/1994 |
| Niue | 05/04/1994 |
| North Macedonia | 07/07/1994 |
| Norway | 07/01/1994 |
| P | |
| Pakistan | 04/08/1994 |
| Palau, Republic of | 10/12/1998 |
| Palestine | 12/18/2015 |
| Panama | 04/07/1994 |
| Papua New Guinea | 05/06/1994 |
| Paraguay | 02/15/1995 |
| Peru | 06/14/1994 |
| Philippines | 06/16/1994 |
| Poland | 04/18/1994 |
| Portugal | 06/17/1994 |
| Q | |
| Qatar | 04/27/2022 |
| R | |
| Romania | 07/29/1994 |
| Russian Federation | 06/23/1994 |
| Rwanda | 06/11/2002 |
| S | |
| Saint Lucia | 03/31/1994 |
| Saint Vincent & the Grenadines | 05/04/1994 |
| Samoa | 03/28/1994 |
| Sao Tome and Principe | 06/07/2002 |
| Senegal | 04/07/1994 |
| Serbia | 09/16/2001 |
| Seychelles, Republic of | 09/20/2001 |
| Sierra Leone | 09/06/1994 |
| Slovak Republic | 11/01/1994 |
| Slovenia | 07/12/1994 |
| Solomon Islands | 04/16/1994 |
| South Africa | 07/06/1994 |
| South Sudan | 04/25/2013 |
| Somalia | 04/11/2007 |
| Spain | 06/09/1994 |
| Sri Lanka | 05/26/1994 |
| St. Kitts and Nevis | 07/25/1994 |
| Sudan | 06/14/1994 |
| Suriname | 05/12/1994 |
| Sweden | 06/28/1994 |
| Switzerland | 07/01/1994 |
| Syria | 04/15/1996 |
| T | |
| Tajikistan | 10/01/1999 |
| Tanzania | 03/26/1996 |
| Thailand | 06/30/1994 |
| Timor-Leste (Democratic Republic of) | 10/06/2003 |
| Togo | 07/21/1994 |
| Tonga | 05/04/1994 |
| Trinidad and Tobago | 05/19/1994 |
| Tunisia | 05/13/1994 |
| Turkey | 07/06/1994 |
| Turkmenistan | 05/29/1997 |
| Tuvalu | 05/03/1994 |
| U | |
| Uganda | 06/28/1994 |
| Ukraine | 06/15/1994 |
| United Kingdom | 06/13/1994 |
| United States | 06/24/1994 |
| Uruguay | 04/22/1994 |
| Uzbekistan | 04/05/1995 |
| V | |
| Vanuatu | 05/19/1994 |
| Venezuela, Republica Bolivariana de | 07/01/1994 |
| Vietnam | 05/12/1994 |
| Y | |
| Yemen | 03/30/1994 |
| Z | |
| Zambia | 06/13/1994 |
| Zimbabwe | 07/07/1994 |