A couplet is a pair of successive lines of verse, usually of the same meter and linked by rhyme. It is one of the most compact and memorable units in English poetry.

Heroic couplets—iambic pentameter lines rhyming aa bb cc—dominated much of eighteenth-century verse; Pope perfected their epigrammatic potential. Shakespeare often closed a scene with a couplet that summarized or pointed the action. Couplets can stand alone as complete poems or serve as building blocks within larger forms. Their brevity encourages closure, wit, and balance.

Not every pair of lines is a couplet; the term implies formal intentionality, usually including rhyme and metrical similarity. Open couplets allow enjambment to flow across the pair; closed couplets complete a thought within the two lines. The form remains popular for its ability to deliver a complete idea with rhythmic finality.

Two lines, matched in meter and joined by rhyme, constitute a couplet.