Hjalmar Frederik Karl Uggla (March 17, 1908 – March 13, 1983) was a Polish soil scientist, professor, and head of the Department of Soil Science at the Higher Agricultural School in Olsztyn (later renamed to the Academy of Agriculture and Technology, now University of Warmia and Mazury in Olsztyn). During World War II, he was a member of a Polish resistance movement. He was also awarded the Righteous Among the Nations prize. He was the father of Andrzej Nils Uggla, a literary studies professor at Uppsala University.