The recorder is a family of woodwind musical instruments and a member of the family of duct flutes that includes tin whistles and flageolets. It is the most prominent duct flute in the western classical tradition. A recorder can be distinguished from other duct flutes by the presence of a thumb-hole for the upper hand and holes for seven fingers: three for the upper hand and four for the lower.

Recorders are made in various sizes and ranges. The sizes most commonly in use today are the soprano (also known as descant, lowest note C₅), alto (also known as treble, lowest note F₄), tenor (lowest note C₄), and bass (lowest note F₃). Recorders were traditionally constructed from wood or ivory. Modern professional instruments are wooden, often boxwood; student and scholastic recorders are commonly made of moulded plastic. The recorders' internal and external proportions vary, but the bore is generally reverse conical (i.e. tapering towards the foot) to cylindrical, and all recorder fingering systems make extensive use of forked fingerings.

The recorder is first documented in Europe in the Middle Ages, and continued to enjoy wide popularity in the Renaissance and Baroque periods, but was little used in the Classical and Romantic periods. It was revived in the twentieth century as part of the historically informed performance movement, and became a popular amateur and educational instrument. Composers who have written for the recorder include Monteverdi, Lully, Purcell, Handel, Vivaldi, Telemann, Bach, Hindemith, and Berio. There are many professional recorder players who demonstrate the full solo range of the instrument, and a large community of amateurs.

The sound of the recorder is often described as clear and sweet, and has historically been associated with birds and shepherds. It is notable for its quick response and its corresponding ability to produce a wide variety of articulations. This ability, coupled with its open finger holes, allow it to produce a wide variety of tone colours and special effects. Acoustically, its tone is relatively pure and, when the edge is positioned in the center of the airjet, odd harmonics predominate in its sound (when the edge is decidedly off-center, an even distribution of harmonics occurs).

The instrument has been known by its modern English name since the fourteenth century. David Lasocki reports the earliest use of "recorder" in the household accounts of the Earl of Derby (later King Henry IV) in 1388, which register i. fistula nomine Recordour (1. a pipe called a 'Recordour').

By the fifteenth century, the name had appeared in English literature. The earliest references are in John Lydgate's Temple of Glas (c. 1430): These lytylle herdegromys Floutyn al the longe day..In here smale recorderys, In floutys. ('These little shepherds fluting all day long ... on these small recorders, on flutes.') and in Lydgate's Fall of Princes (c. 1431–1438): Pan, god off Kynde, with his pipes seuene, / Off recorderis fond first the melodies. ('Pan, god of Nature, with his pipes seven, / of recorders found first the melodies.')

Appending the name recorder to the instrument itself is uniquely English: In Middle-French there is no equivalent noun sense of recorder referring to a musical instrument. The English verb record (from Middle-French recorder, early thirteenth century) meant "to learn by heart, to commit to memory, to go over in one's mind, to recite"; but the term did not refer to playing music until the sixteenth century. It was long after the English recorder was so-named that it gained two additional meanings: "silently practicing a tune", or "sing or render in song"—both referring almost-exclusively to songbirds.

Partridge indicates that the use of the instrument by jongleurs led to its association with the verb: Recorder the minstrel's action, a recorder the minstrel's tool. The reason is uncertain why this flute instrument—rather than some other instrument played by the jongleurs—is known as the recorder.