The saxotromba is a valved brass instrument invented by the Belgian instrument-maker Adolphe Sax around 1844. It was designed for the mounted bands of the French military, probably as a substitute for the French horn. The saxotrombas comprised a family of half-tube instruments of different pitches. By about 1867 the saxotromba was no longer being used by the French military, but specimens of various sizes continued to be manufactured until the early decades of the twentieth century, during which time the instrument made sporadic appearances in the opera house, both in the pit and on stage. The instrument is often confused with the closely related saxhorn.

Antoine-Joseph "Adolphe" Sax was a Belgian inventor and musician who invented the saxophone in the early 1840s, patenting it in 1846. He also invented the saxotromba, saxhorn and saxtuba, and redesigned the bass clarinet in a fashion still used to the present day. He played the flute and clarinet.