Couesnon is a French manufacturer of brass and percussion instruments founded in 1827 in Château-Thierry, a town on the Marne River known for its tradition of brass instrument making. The company was acquired by the Couesnon family in 1883 and grew under the direction of Amédée Couesnon into one of France's largest instrument makers, expanding to eleven factories and more than a thousand workers by the early 1910s. Couesnon won numerous awards for technical innovation and supplied a wide range of products including trumpets, cornets, flugelhorns, French horns, tubas, saxophones, woodwinds, and military bugles.

From the 1930s onward, the company became closely associated with French fanfare (marching brass) bands, eventually becoming the dominant supplier of marching brass instruments in France while ceding the orchestral and jazz trumpet markets to makers such as Selmer, Courtois, and Conn. Vintage Couesnon trumpets, cornets, and saxophones from the late 19th and early 20th centuries remain collectible on the secondhand market.

In 1999 the French drum maker P.G.M. acquired the Couesnon name, tooling, and factory, continuing production under the PGM-Couesnon name from a workshop in Nogent-l'Artaud. The revived workshop focuses on hand-built brass band and ceremonial instruments — flugelhorns, cornets, tubas, French horns, hunting horns, natural trumpets (including the Jeanne d'Arc model), cavalry trumpets, and military bugles — alongside the tambour drums and other percussion that are central to French marching tradition.

Couesnon has 1 product cataloged on Equipboard, including Trumpets.