| Name | Other Name | Family | Nativ Name | ISO6391 Code | ISO6392T Code | ISO6392B Code | ISO6393 Code | Notes |
|---|---|---|---|---|---|---|---|---|
| Swahili | Niger–Congo | Kiswahili | sw | swa | swa | swa + 2 | macrolanguage | |
| Sundanese | Austronesian | Basa Sunda | su | sun | sun | sun | ||
| Swati | Niger–Congo | SiSwati | ss | ssw | ssw | ssw | also known as Swazi | |
| Serbian | Indo-European | српски језик | sr | srp | srp | srp | The ISO 639-2/T code srp deprecated the ISO 639-2/B code scc | |
| Sardinian | Indo-European | sardu | sc | srd | srd | srd + 4 | macrolanguage | |
| Albanian | Indo-European | Shqip | sq | sqi | alb | sqi + 4 | macrolanguage; "Albanian Phylozone" in 639-6 | |
| Spanish | Castilian | Indo-European | Español | es | spa | spa | spa | |
| Southern Sotho | Niger–Congo | Sesotho | st | sot | sot | sot | ||
| Somali | Afro-Asiatic | Soomaaliga; af Soomaali | so | som | som | som | ||
| Sindhi | Indo-European | सिन्धी; سنڌي، سندھی | sd | snd | snd | snd |