The grapheme Š, š (S with caron) is used in various contexts representing the sh sound like in the word show, usually denoting the voiceless postalveolar fricative /ʃ/ or similar voiceless retroflex fricative /ʂ/.

The symbol originates with the 15th-century Czech alphabet that was introduced by the reforms of Jan Hus.

[1][2] From there, it was first adopted into the Croatian alphabet by Ljudevit Gaj in 1830 to represent the same sound,[3] and from there on into other orthographies, such as Latvian,[4] Lithuanian,[5] Slovak,[6] Slovene, Karelian, Sami, Veps and Sorbian.

The symbol is also used as the romanization of Cyrillic ш in ISO 9 and scientific transliteration and deployed in the Latinic writing systems of Macedonian, Bulgarian, Serbian, Belarusian, Ukrainian, and Bashkir.

In addition, the grapheme transliterates cuneiform orthography of Sumerian and Akkadian /ʃ/ or /t͡ʃ/, and (based on Akkadian orthography) the Hittite /s/ phoneme, as well as the /ʃ/ phoneme of Semitic languages, transliterating shin (Phoenician and its descendants), the direct predecessor of Cyrillic ш.