Friedrich Joseph Adalbert Seitz, (24 February 1860 in Mainz – 5 March 1938 in Darmstadt) was a German physician and entomologist who specialised in Lepidoptera. He was a director of the Frankfurt zoo from 1893 to 1908 and is best known for editing the multivolume reference on the butterflies and larger moths of the world Die Gross-Schmetterlinge der Erde which continued after his death.