Johann Caspar Ferdinand Fischer (c.1670 - 1746) was a German composer.

He seems to have been of Bohemian origin, but details about his life are sketchy. By 1695 he was Kapellmeister to Ludwig Wilhelm of Baden, and he may have remained with the court until his death in Rastatt.

Much of Fischer's music, such as the orchestral suites in Le journal du printems (1695), shows the influence of the French Baroque style exemplified by Jean Baptiste Lully. His Ariadne musica for organ, with its twenty preludes and fugues in nineteen different keys and one in the Phrygian mode based on E, is considered a significant precursor to Johann Sebastian Bach's Das wohltemperierte Klavier (it is not clear whether Bach knew this particular piece, though he was familiar with Fischer's work in general).