Johan Peter Koch (15 January 1870 – 13 January 1928) was a Danish captain and explorer of the Arctic dependencies of Denmark, born at Vestenskov.
J.P. Koch participated in Amdrup's expedition to east Greenland in 1900 and was one of the general staff of the surveying expeditions to Iceland in 1903-1904.
In 1906-1908 he was a member of the Danmark expedition led by Ludvig Mylius-Erichsen, which mapped the last pieces of the northeastern coast of Greenland. On the death of Mylius-Erichsen and two others on a long sled voyage from Danmarkshavn to Peary Land, Koch along with the Greenlander Tobias Gabrielsen searched for the lost party, and found only the Greenlander Jørgen Brønlund on whose body were recovered hand drawn charts which completed the map of Greenland.
In 1907 Koch, together with Aage Bertelsen, was reported to have first seen Fata Morgana Land (Danish: Fata Morgana Landet), a phantom island supposedly lying between NE Greenland and Svalbard. This elusive land was allegedly seen as well by Lauge Koch from the air in 1933.
Koch later led a sled expedition across the inland ice of Greenland in 1912-13, with Alfred Wegener.
Koch received, among other honors, the Vega medal of the Swedish Society for Anthropology and Geography. He also became a member of the International Polar Commission.