The third smallest member of the saxophone family. Soprano saxophones are the smallest and highest saxophone in common use.

A transposing instrument pitched in the key of B flat, a modern soprano saxophone has all the keys of other saxophone models (with the exception of the low A on some baritones and altos) and has a range from low B flat to high F sharp and is therefore pitched one octave above the tenor saxophone.

Many sopranos made since the 1990s feature detachable necks and will include one straight and one downward-curved neck. A fully straight soprano must be held upward and outward while playing, which allows it to project well and can allow for a more energetic appearance in performance. A curved neck allows the instrument to be held somewhat downward and still maintain a proper mouthpiece angle, which makes for easier use of a music stand and can reduce fatigue in the right arm for some players. Some also believe that a curved neck gives the soprano a warmer, less nasal tone, although this is debated.

Due to the higher pitch of the soprano, it is more sensitive with respect to intonation than the lower saxophones, so a player must have more skill with breath support, tongue and soft palate position, and embouchure (collectively known as voicing). It is also less forgiving of poor maintenance than lower saxophones.