Fritz (Friedrich) Seitz (12 June 1848, Gunthersleben-Wechmar, Saxe-Coburg and Gotha – 22 May 1918) was a German Romantic Era composer. He was a violinist who served as a concertmaster, who wrote chamber music and five student concertos for the violin.
Seitz studied violin first under Karl Wilhelm Uhlrich in Sondershausen, Germany; he later married Uhlrich's daughter. He became a student of Johann Christoph Lauterbach in 1874. He became music director at Sondershausen, and thereafter became concertmaster at Magdeburg. In 1884 he was the “Hofkonzertmeister” (conductor of the court orchestra) at Dessau.
Movements from Seitz' student concerti (No 2 and No 5) have become more widely known by virtue of their wide popularity as instructive violin pieces.