Johan Maurits Mohr (ca. 18 August 1716,Eppingen – 25 October 1775,Batavia) was aDutch-Germanpastor who studied atGroningen University from 1733 and settled inBatavia (Dutch East Indies) in 1737. Mohr's greatest passion was inastronomy but he was also keenly interested inmeteorology and invulcanology.

In 1765 Mohr built alarge private observatory in Batavia that was equipped with the best astronomical instruments of his time.^[1] His observatory, which had cost him a small fortune, was visited and praised byLouis Antoine de Bougainville andJames Cook.

Mohr observed theVenus transits of 6 June 1761 and 3 June 1769 and theMercury transit of 10 November 1769. He also made meteorological observations and measurements of themagnetic declination at Batavia.

After Mohr's death, his observatory was damaged by an earthquake in 1780, fell into ruin and was demolished in 1812.^[1]

The minor planet5494 Johanmohr is named in his honour.

• H.J. Zuidervaart & R.H. van Gent, " "A Bare Outpost of Learned European Culture on the Edge of the Jungles of Java": Johan Maurits Mohr (1716-1775) and the Emergence of Instrumental and Institutional Science in Dutch Colonial Indonesia",Isis: An International Review devoted to the History of Science and its Cultural Influences, 95 (2004), 1-33.

• List of colonial buildings and structures in Jakarta

• 1716 births
• 1775 deaths
• 18th-century Dutch astronomers
• Dutch Protestant ministers and clergy
• Colonial architecture in Jakarta
• People from Heilbronn (district)
• University of Groningen alumni
• Dutch East India Company people