Parties and Range States
| Title | Status | Status date | CMS Party number | Region |
|---|---|---|---|---|
| Slovenia | Party | 1999 | 057 | Europe |
| Solomon Islands | Non-Party | AM | Oceania | |
| Somalia | Party | 1986 | 020 | Africa |
| South Africa | Party | 1991 | 038 | Africa |
| South Sudan | Non-Party | Africa | ||
| Spain | Party | 1985 | 017 | Europe |
| Sri Lanka | Party | 1990 | 033 | Asia |
| Sudan | Non-Party | AM | Africa | |
| Suriname | Non-Party | South & Central America & The Caribbean | ||
| Svalbard and Jan Mayen (Norway) | Party | 1985 | 018 | Europe |
| Sweden | Party | 1983 | 001 | Europe |
| Switzerland | Party | 1995 | 046 | Europe |
| Syrian Arab Republic | Party | 2003 | 082 | Asia |
| Tajikistan | Party | 2001 | 071 | Asia |
| Thailand | Non-Party | AM | Asia | |
| Timor-Leste | Non-Party | Oceania | ||
| Togo | Party | 1996 | 048 | Africa |
| Tonga | Non-Party | AM | Oceania | |
| Trinidad and Tobago | Party | 2018 | 127 | South & Central America & The Caribbean |
| Tunisia | Party | 1987 | 023 | Africa |