长音符［日语：长音符／ちょうおんぷ，又称音引（音引き／おんびき）、棒引（棒引き／ぼうびき）］，是在日语中用来表示拉长字音的符号。通常写作ー，直写为「丨」，书写时用在对应假名之后。长音符通常用在片假名中，平假名中较少见，而且从不用在罗马字中。

长音符有时会出现于平假名中，如拉面馆招牌上有时会用平假名写成らーめん，然而一般情况下平假名通常不用长音符表示长音，而是在假名后面加上一个あ行的假名表示长音。下表以は行的假名举例：

The chōonpu(长音符), also known as chōonkigō(长音记号), onbiki(音引き), bōbiki(棒引き), or Katakana-Hiragana Prolonged Sound Mark by the Unicode Consortium, is a Japanese symbol which indicates a chōon, or a long vowel of two morae in length. Its form is a horizontal or vertical line in the center of the text with the width of one kanji or kana character. It is written horizontally in horizontal text and vertically in vertical text. The chōonpu is usually used to indicate a long vowel sound in katakana writing, rarely in hiragana writing, and never in romanized Japanese. The chōonpu is a distinct mark from the dash, and in most Japanese typefaces it can easily be distinguished. In horizontal writing it is similar in appearance to, but should not be confused with, the kanji character 一 ("one").