Johan Aschehoug Kiær

Johan Aschehoug Kiær (October 11, 1869 – 1931) was a Norwegian paleontologist and geologist.

He was born in Drammen as the son of Hagbarth Kiær (1829–1903). In 1909 he was appointed professor of paleontology at the University of Oslo, as the first in Norway to hold such a position. He was also head of the Palaeontological Museum of Oslo.His most important publication was Das Obersilur im Kristianiagebiete.He took part in work on Spitsbergen.He work covered corals, trilobites, and especially Devonian and Silurian fishes.

He was an important inspiration for the work of Anatol Heintz.

Johan Aschehoug Kiær was the grandson of Hans Andersen Kiær and nephew of Anders F. Kiær and Hans Theodor Kiær, all businessmen. He was a first cousin of Elias C. Kiær and Frits Kiær.