The circumflex ( ˆ ) is a diacritic used in the written forms of many languages, and is also commonly used in various romanization and transcription schemes. It received its English name from Latin circumflexus (bent around)—a translation of the Greek περισπωμένη (perispōménē). The character is also used in mathematics, where it is typically called hat or roof.

For actually adding the diacritic to a base letter (as in â), Unicode has U+0302 ◌̂ combining circumflex accent. In addition, the ISO-8859-1 character encoding includes the precomposed characters â, ê, î, ô, û (as well as their respective capital forms), and dozens more are available in Unicode.

There is a similar but larger character, U+005E ^ circumflex accent (spacing, so not combining), which is also included in ASCII but often referred to as caret instead. It is, however, unsuitable for use as a diacritic, as it is a spacing character. Another spacing circumflex character in Unicode is the smaller U+02C6 ˆ modifier letter circumflex, mainly used in phonetic notations.