Voiceless postalveolar fricative

This is also known as a voiceless palatal fricative /ʃ/, but not a true palatal, such as ç. In many languages, this is written as a digraph, but it's not always the case.

Germanic Languages

Anglo-Saxon

In Anglo-Saxon, the digraph sc when around a front vowel becomes /ʃ/.

Modern English

Modern English has several digraphs which can be used to form the sound /ʃ/. The most basic form is the spelling sh. However, there are others spellings. The digraph ch is used as /ʃ/ in words from French (such as chef and champagne). In the noun ending -tion, most of the time the initial sound is turned into a /ʃ/ (combination, redemption, and creation). Related to that is the digraph -ti- in several words (such as initial). The last one is often the spelling ss or simple s (such as tissue, fissure, or sure). In some German loanwords, the combination sch is used (schadenfreude, schnapps schnauzer).

High German and Low German

In High and Low German, the trigraph sch is used to form the sound /ʃ/.

Dutch

The digraph sj is used for /ʃ/. It should be noted that the trigraph sch is pronounced /sx/ rather than /ʃ/.

Norwegian

In Norwegian, this sound is produced by the combination sk before j, i, or y or sj. Some dialects vary on this.

Swedish

In Swedish, the digraph ch is used for /ʃ/, especially when it's after a front vowel (i, y, e, ä, or ö).

Romance Languages

French

The digraph ch is pronounced /ʃ/ in French.

Italian

Italian has a digraph which differs by the frontness of the vowel. The digraph sc when preceding an i or e becomes /ʃ/. Words like coscienza (conscience) /cɔʃjɛnʦa/, or riusciva (it succeeded) /rjuʃiva/.

Romanian

The letter Ş,ş is used for /ʃ/ in Romanian. The nickname of the legendary ruler, Vlad Ţepeş (Vlad the Impaler), was pronounced /vlad ʦepeʃ/.

Slavic Languages

Russian

In the Cyrillic alphabet, /ʃ/ is represented by Ш ш, although in some dialects other sounds such as /ɕ/ or sometimes /ç/ are pronounced for this symbol.
Also, Щ, щ is pronounced /ʃʧ/, which can be split up when inside in bi-syllabic conditions.