Marples' penguin (Palaeeudyptes marplesi) was a large species of the extinct penguin genus Palaeeudyptes. It stood between 105 and 145 cm high in life, larger than the present emperor penguin. The precise relationship between this species and the slightly smaller narrow-flippered penguin (Palaeeudyptes antarcticus) from somewhat younger rocks is not resolved; possibly, P. marplesi is a synonym or subspecies of P. antarcticus. The binomen of this species honors Brian J. Marples, one of the foremost researchers of fossil penguins in the 20th century.