word | | Country name |
| conventional | Spain | conventional long form: Kingdom of Spain conventional short form: Spain local long form: Reino de Espana local short form: Espana |
| conventional | Spratly Islands | conventional long form: none conventional short form: Spratly Islands |
| conventional | Sri Lanka | conventional long form: Democratic Socialist Republic of Sri Lanka conventional short form: Sri Lanka local long form: Shri Lamka Prajatantrika Samajaya di Janarajaya/Ilankai Jananayaka Choshalichak Kutiyarachu local short form: Shri Lamka ... |
| conventional | Sudan | conventional long form: Republic of the Sudan conventional short form: Sudan local long form: Jumhuriyat as-Sudan local short form: As-Sudan former: Anglo-Egyptian Sudan |
| conventional | Suriname | conventional long form: Republic of Suriname conventional short form: Suriname local long form: Republiek Suriname local short form: Suriname former: Netherlands Guiana, Dutch Guiana |
| conventional | Svalbard | conventional long form: none conventional short form: Svalbard (sometimes referred to as Spitsbergen) |
| conventional | Swaziland | conventional long form: Kingdom of Swaziland conventional short form: Swaziland local long form: Umbuso weSwatini local short form: eSwatini |
| conventional | Sweden | conventional long form: Kingdom of Sweden conventional short form: Sweden local long form: Konungariket Sverige local short form: Sverige |
| conventional | Switzerland | conventional long form: Swiss Confederation conventional short form: Switzerland local long form: Schweizerische Eidgenossenschaft (German); Confederation Suisse (French); Confederazione Svizzera (Italian); Confederaziun Svizra (Romansh) local short form: Schweiz (German); Suisse (French); Svizzera ... |
| conventional | Syria | conventional long form: Syrian Arab Republic conventional short form: Syria local long form: Al Jumhuriyah al Arabiyah as Suriyah local short form: Suriyah former: United Arab Republic (with Egypt) |