Christian Gottlob Keyser (also spelled Keysser, Kaiser) was a Lutheran missionary of the Neuendettelsau Mission Society.
He served for almost 22 years at the Neuendettelsau Mission Station in the Finschhafen District of New Guinea, which had been founded in 1892 by Johann Flierl.
An intrepid explorer, he ascended the Saruwaged Range massif in 1913 and collected many important natural history specimens there.
In 1903, he performed the first group baptism; although it was only ten people, it was a start, and laid the groundwork for the mass conversions of 1905 and 1906 (the latter being helped somewhat by a rough earthquake in September 1906).
During his years at the Sattelberg, he undertook frequent scientific journeys, and was a regular correspondent of the German Geographical Society of Berlin.