Louis Spohr ([ˈluːi ˈʃpo:ɐ], 5 April 1784 – 22 October 1859), baptized Ludewig Spohr, later often in the modern German form of the name Ludwig was a German composer, violinist and conductor.

Highly regarded during his lifetime, Spohr composed ten symphonies, ten operas, eighteen violin concerti, four clarinet concerti, four oratorios, and various works for small ensemble, chamber music, and art songs. Spohr invented the violin chinrest and the orchestral rehearsal mark. His output spans the transition between Classical and Romantic music, but fell into obscurity following his death, when his music was rarely heard. The late twentieth century saw a modest revival of interest in his oeuvre primarily in Europe, but his reputation has never been restored to that of his lifetime.