Bjørn Helland-Hansen (16 October 1877 – 7 September 1957) was a Norwegian pioneer in the field of modern oceanography.

He studied the variation patterns of the weather in the northern Atlantic Ocean and of the atmosphere.

He developed the "Helland-Hansen Photometer" in 1910, which was carried on board Michael Sars.

From 1946 to 1948, Helland-Hansen was President of the International Union of Geodesy and Geophysics (IUGG).

Helland-Hansen trained Alexander Kuchin, the Russian oceanographer who went to Antarctica with Roald Amundsen.