The ophicleide, a brass instrument, is part of the family of keyed bugles invented by Jean Hilaire Asté (often called Halary) in the early 1800s. While the soprano members of the family (in E-flat, C, and B-flat, at least) were made in a single horizontal coil (in the shape of a bugle), the larger members were made upright (in the shape of a bassoon). The first instruments were made with 9 keys, while later models were equipped with 11 or 12. A few unusual models had valves as well. One had three valves, making it virtually a primitive tuba, and one had a valve and 5 keys.

The name ophicleide means "keyed serpent", and in fact the ophicleide was developed as an improvement over the traditonal wooden serpent. The serpent is difficult to play in tune and has a soft timbre. Its tone holes are arranged where one can reach them, rather than where they have the best effect acoustically. Halary revised the entire concept, making the bore of metal, positioning 9 tone holes in approximately correct locations, and covering the large holes with padded keys. Additional keys were added later to improve particular notes. However, the keys are not arranged to make sense to woodwind players: keys reach from the tone hole to the nearest finger (or thumb). Learning the fingerings is more like learning valve combinations.

The ophicleide was made in a variety of sizes, from the alto size (quinticlave) in E-flat and F, and the bass in C and B-flat, to the rare contrabass in E-flat. The size most often found today is the bass, having a range corresponding roughly to the bassoon.

In the 1850s, the tuba was developed, and soon the ophicleide was obsolete. However, the Paris Symphony Orchestra listed one as late as 1916.

Today, the ophicleide is still used to play music written in the 1800s that calls for the instrument. The ophicleide was included in the orchestra in the following representative works:

• Auber: La Muette de Portici
• Berlioz: The Damnation of Faust, Benvenuto Cellini, Fantastic Symphony, The Trojans
• Mendelssohn: Elijah, Midsummer Night's Dream
• Meyerbeer: l'Africaine, Les Huguenots, Robert le Diable
• Schumann: Paradies und die Peri
• Spontini: Olimpie
• Wagner: Rienzi