Christian Jacob Hedemann (25 May 1852 – 18 May 1932) was a Danish mechanical engineer who settled in Hawaii in 1878, where he worked at the Hana Sugar Plantation and the Honolulu Iron Works. He is, however, remembered primarily as an avid amateur photographer who helped found the Hawaiian Camera Club (1889–1893). His photographs of native peoples, landscape, family, and industry offer a unique pictorial record of Hawaii at the end of the 19th century.
Christian Hedemann was born in 1852 at Flensburg in Schleswig-Holstein, which at the time was part of the Kingdom of Denmark. He was the son of Christian August Ferdinand Hedemann (1810-1879), an eminent surgeon in the Danish army, and Caroline Amalie Cloos (1824-1867). After attending primary school in Næstved, he continued his education at Herlufsholm School and graduated with first class honours in mechanical engineering at the Polytechnic College in Copenhagen. After an apprenticeship in a machine shop, he was employed as a designer by Burmeister & Wain in Copenhagen (1874–78). In October 1877, he married Meta Marie Magdalena Nissen (1850-1952).