The voiceless retroflex sibilant fricative is a type of consonantal sound used in some spoken languages.

The symbol in the International Phonetic Alphabet that represents this sound is ⟨ʂ⟩ which is a Latin letter s combined with a retroflex hook.

Only one language, Toda, appears to have more than one voiceless retroflex sibilant, and it distinguishes subapical palatal from apical postalveolar retroflex sibilants; that is, both the tongue articulation and the place of contact on the roof of the mouth are different.

Some scholars also posit the voiceless retroflex approximant distinct from the fricative.

Features of the voiceless retroflex fricative: In the following transcriptions, diacritics may be used to distinguish between apical [ʂ̺] and laminal [ʂ̻].