In music, a medley is a piece composed from parts of existing pieces, usually three, played one after another, sometimes overlapping. They are common in popular music, and most medleys are songs rather than instrumental. A medley which is a remixed series is called a megamix, often done with tracks for a single artist, or for popular songs from a given year or genre.

A medley is the most common form of overture for musical theater productions.

In Latin music, medleys are known as potpourrís or mosaicos; the latter were popularized by artists such as Roberto Faz and Billo Frómeta, and most commonly consist of boleros, guarachas, merengues or congas.