Carl Johannes Louis Langhein (29 February 1872, Hamburg – 26 June 1941, Hadamar) was a German painter and graphic artist.
He was born to Carl Jacob Martin Langhein (1846–1914), an upholsterer and decorator, and his wife, Louise Catharina Maria née Westphal (1849–1873).
He continued his studies at the Academy of Fine Arts, Karlsruhe, with Carlos Grethe and Robert Poetzelberger.
In 1897, he became managing director of the newly created Kunstdruckerei Künstlerbund Karlsruhe [de] (fine art printers' association), a position he would hold until 1926.
During World War I, he served in the Imperial German Navy, with the rank of Lieutenant, and was awarded the Hanseatic Cross.