Flute names both a family of instruments and a single instrument. It is a member of the woodwind group. The various flutes are the only non-reed woodwind instruments found in the orchestra, all the rest being either single reeds, like the clarinet, or double reeds, like the oboe and bassoon.

The standard members of the transverse flute family are as follows, arranged from lowest pitched to highest pitched. Each of the various flutes has a several-octave range. They are all written at more or less the same place on the staff, but their sounding pitches are different. Notice that there are two that extend the flute’s range downwards, and two that extend it upwards.

• Bass flute, the lowest flute, sounds an octave lower than written.
• Alto flute in G sounds a perfect fourth lower than written.
• Concert Flute is a non-transposing instrument, played by a flautist or flutist.
• Flute in Eb sounds a minor third higher than written.
• Piccolo sounds an octave higher than written.

Related instruments are the end blown flutes, a group that includes the recorder or fipple flute, the Native American flute, the flageolet, and the tin whistle or pennywhistle. The ocarina is also related; as is the transverse flute called the fife, the primary use of which is in combination with drums in marching or military bands; and various pan flutes, usually made of multiple pipes that are used to change pitch, rather than using holes or keys.

The flute is used in both band and orchestra. In both ensembles, one of the flute players usually doubles on piccolo. The flute is also a member of the wind ensemble, woodwind ensemble, and the woodwind quintet, in which it performs along with clarinet, oboe, bassoon, and French horn. It is also characteristically found in woodwind trios and quartets, though these do not have fixed membership, as the woodwind quintet does.

The flutes are the oldest category of woodwind instrument. There were flutes as early as the ninth century BCE. The basic design is a tube with an embouchure hole into which the player blows and finger holes to control the pitch. The modern flute was developed in 1830 by Theobald Boehm and incorporates his fingering system. Flutes and piccolos were both originally made of wood, but now they are generally metal.

A flute has three parts: the head joint, which holds the embouchure hole; the body, which is the largest piece; and the foot joint, which is the end of the flute. Famous flute parts include the first movement of Czech composer Antonin Dvořák’s Symphony No. 9, "From the New World;" French composer Claude Debussy’s L’Aprés-midi d’un Faune; and French composer Georges Bizet’s Carmen, particularly the "Prelude to Act III." Paula Robeson, Jean-Pierre Rampal, and James Galway are well-known flutists.