This article is about the breve as a diacritical mark. For a breve in music, see double whole note.

A breve (Latin Brevis "short, brief") is a diacritical mark ˘, shaped like a little round cup, designed to indicate a short vowel, as opposed to the macron ¯ which indicates long vowels. It is used this way in dictionaries and textbooks of Latin and some other languages. It looks similar to caron or háček, but the caron has a sharp tip, whilst the breve is rounded. Compare Ǎ ǎ Ě ě Ǐ ǐ Ǒ ǒ Ǔ ǔ (hacek) with Ă ă Ĕ ĕ Ĭ ĭ Ŏ ŏ Ŭ ŭ (breve).

In the Cyrillic alphabet, a breve is used for Й (short I). In Belarusian, it is used for both the Cyrillic Ў (U short) and Latin (Łacinka) Ŭ. Ў was also used in Cyrillic Uzbek under the Soviet Union. In the Chuvash a breve is used for Cyrillic letters Ӑ (A-breve) and Ӗ (Ye-breve).

In other languages, it is used for other purposes. In Romanian it can be used above the A to form the schwa (ə) vowel and in Esperanto it can be used above the U to form a non-syllabic U, similar to english W in sound.

Breve together with acute, grave, circumflex, horn, tilde, and dot are used in the Vietnamese language.

Note that pinyin uses hacek to indicate the third tone of Mandarin Chinese, not breve.