十四行诗（英语：Sonnet），音译商籁，是一种定型诗的类型，起源于意大利，一般相信是由贾科莫·达·伦蒂尼（Jacopo da Lentini）创始，于十三世纪时期形成，之后传布到欧洲各国。

十四行诗的原始字面意思，是小诗、小歌谣的意思。在13世纪时，14行诗被定型下来，由十四句诗句组成，其押韵结构与文本构成皆有严格限制。但是随着历史演变，这些约定俗成的限制也有所改变。现在常见的是意大利类（彼特拉克类）或英国类（莎士比亚类）。

A sonnet is a poetic form which originated in Italy; Giacomo Da Lentini is credited with its invention.

The term sonnet is derived from the Italian word sonetto (from Old Provençal sonet a little poem, from son song, from Latin sonus a sound). By the thirteenth century it signified a poem of fourteen lines that follows a strict rhyme scheme and specific structure. Conventions associated with the sonnet have evolved over its history. Writers of sonnets are sometimes called "sonneteers", although the term can be used derisively.