Çavuş, also anglicized Chaush and Chiaus[1] (from Turkish: çavuş / چاوش; Arabic: شاويش, romanized: shawish;[2] from Old Turkic Çabuş or Çawuş, "person who gives order or yells")[3] was an Ottoman title used for two separate soldier professions, both acting as messengers although differing in levels.

[4] It was a rank below agha and kethüda (from Persian, kad-khuda, "magistrate"), in units such as the Janissaries and Sipahi, and was also a term for members of the specialized unit of çavuşān (چاوشان, also çavuşiyye,[5] çavuş(an)-i divan(i)[4]) consisting of combined cavalry and infantry serving the Imperial Council (as in Ottoman Egypt).

[6] The çavuşbaşı was an assistant (or deputy) to the Grand Vizier,[7] dealing with security matters,[8] accompanying ambassadors visiting the Grand Vizier,[4] and also carried out the first examination of petitions submitted to the council, and led council meetings when the Grand Vizier was not present.

In the past in former Yugoslavia, the word čauš was also sometimes applied to the wedding-planner.

Çavuş also serves as the root word for the rest of the non-commissioned officer rank names.