The close front rounded vowel, or high front rounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨y⟩, and the equivalent X-SAMPA symbol is y. Across many languages, it is most commonly represented orthographically as ⟨ü⟩ (in German, Turkish, Estonian and Hungarian) or ⟨y⟩ (in Danish, Norwegian, Swedish, Finnish and Albanian) but also as ⟨u⟩ (in French and Dutch and the Kernewek Kemmyn standard of Cornish); ⟨iu⟩/⟨yu⟩ (in the romanization of various Asian languages); ⟨уь⟩ (in Cyrillic-based writing systems such as that for Chechen); or ⟨ү⟩ (in Cyrillic-based writing systems such as that for Tatar).

Short /y/ and long /yː/ occurred in pre-Modern Greek. In the Attic and Ionic dialects of Ancient Greek, front [y yː] developed by fronting from back /u uː/ around the 6th to 7th century BC. A little later, the diphthong /yi/ when not before another vowel monophthongized and merged with long /yː/. In Koine Greek, the diphthong /oi/ changed to [yː], likely through the intermediate stages [øi] and [øː]. Through vowel shortening in Koine Greek, long /yː/ merged with short /y/. Later, /y/ unrounded to [i], yielding the pronunciation of Modern Greek. For more information, see the articles on Ancient Greek and Koine Greek phonology.

The close front rounded vowel is the vocalic equivalent of the labialized palatal approximant [ɥ]. [y] alternates with [ɥ] in certain languages, such as French, and in the diphthongs of some languages, ⟨y̑⟩ with the non-syllabic diacritic and ⟨ɥ⟩ are used in different transcription systems to represent the same sound.

In most languages, this rounded vowel is pronounced with compressed lips ('exolabial'). However, in a few cases the lips are protruded ('endolabial').