Hjalmar Heiberg (1837 – 1897) was a Norwegian physician, and a professor of anatomy at the University of Oslo. His research speciality was inflammations, and he was a proponent for the new theory of bacteria. He was the son of Christen Heiberg, and the father of Jean Heiberg. He was decorated Knight, First Class of the Royal Norwegian Order of St. Olav in 1890.[1][2]