Ogonek (Polish for little tail) is a diacritic hook placed under the lower right corner of a vowel in the Latin alphabet used in Polish, Lithuanian, Navajo, Western Apache, Chiricahua and Tutchone. It is also used in academic transliteration of Old Church Slavonic and Old Norse. In Polish, Old Church Slavonic, Navajo, Western Apache, and Chiricahua it indicates that the vowel is nasalized ; in Lithuanian it formerly indicated nasalization but this is no longer distinctive. In Navajo it can be combined with the acute accent.

Ogonek should be almost the same size as the lower part of such letters as p or g; (in larger type sizes may be relatively quite shorter) and should not be confused with the cedilla or comma diacritic marks used in other languages.

Example in Polish:

Po co pan tak brzęczy w gąszczu?”

— Jan Brzechwa, Chrząszcz

The HTML/Unicode numbers for ogonek letters are: