August von Pelzeln was an Austrian ornithologist. He was a grandson to novelist Karoline Pichler.
He studied at the University of Vienna, later working as an assistant under helminthologist Karl Moriz Diesing in the Hof-Naturalien-Cabinet. In 1857 he acquired curatorial duties formerly held by Johann Jakob Heckel, and subsequently became in charge of the bird and mammal collections. He worked on the birds collected by Johann Natterer in Brazil.
He was forced to retire from the museum due to ill health, and died at Oberdöbling near Vienna.
Some birds described by Pelzeln are the orange-breasted thornbird, the spot-winged antbird, the red-legged tinamou, the white-throated tinamou, the short-billed leaftosser, the yellow-margined flatbill and the New Zealand rockwren.
His name is associated with Pelzeln's tody-tyrant. Gustav Hartlaub named the Madagascar grebe in his honor; Otto Finsch named the Pohnpei starling after Pelzeln.