A back vowel is a type of vowel sound used in some spoken languages. The defining characteristic of a back vowel is that the tongue is positioned as far back as possible in the mouth without creating a constriction that would be classified as a consonant. The back vowels identified by the International Phonetic Alphabet are:

• close back unrounded vowel [ɯ]
• close back rounded vowel [u]
• close-mid back unrounded vowel [ɤ]
• close-mid back rounded vowel [o]
• open-mid back unrounded vowel [ʌ]
• open-mid back rounded vowel [ɔ]
• open back unrounded vowel [ɑ]
• open back rounded vowel [ɒ]

See also: List of phonetics topics