Johann Reinder Erlers Lutjeharms (13 April 1944 - 8 June 2011), was a leading South African marine scientist and an authority in the oceanography of the Agulhas Current, who authored a definitive work on the subject, The Agulhas Current (Springer 2006).
His main field of investigation was the large-scale circulation patterns of the oceans adjacent to southern Africa and their influence on weather and climate, and he participated in 17 research cruises and was responsible for a further 48 projects undertaken on such cruises.