Kanstul Musical Instruments is an American brass instrument maker based in Anaheim, California, founded in 1981 by Zigmant "Ziggy" Kanstul. Before starting his own company, Ziggy spent decades at F.E. Olds & Son in Los Angeles, where he became an expert in brass instrument design and manufacturing. Joined by his sons Jack and Mark, the family built Kanstul into a respected workshop producing trumpets, cornets, flugelhorns, trombones, and tubas, and at various points manufacturing instruments under marques such as F. Besson.

The company is best known for its hand-built professional trumpets, including rotary valve models developed in collaboration with players like Richard Carson Steuart and Claudio Roditi, the California Series trumpets, and the Doc Severinsen Destino line designed for the longtime Tonight Show bandleader. Kanstul also produced signature artist models such as the Alan Kaplan tenor trombone, alongside a wide catalog of slides, mouthpieces, and components.

Though Ziggy passed away in 2016, the Kanstul name continues to be associated with handcrafted, custom-tailored brasswinds and a small-shop approach to instrument making. The brand maintains an extensive archive of its catalog and history, with the family carrying forward Ziggy's legacy under the banner "Honoring the Legacy. Building the Future."

Kanstul has 4 products cataloged on Equipboard, including Trumpets, Mouthpieces, and Trombones. Their gear is featured by 2 artists, with the strongest followings in Rock. Notable users include Lee Loughnane and John Christianson.