Gustaaf Willem, Baron van Imhoff (8 August 1705 – 1 November 1750) was a Dutch colonial administrator for the Dutch East India Company (VOC). He served as Governor of Ceylon from 1736 to 1740 and as Governor-General of the Dutch East Indies from 1743 until his death in 1750.
Van Imhoff was born into an East Frisian aristocratic family. His father, Wilhelm Heinrich Freiherr von Imhoff, came from the town of Leer in northwestern Germany, a few kilometers from the Dutch border.
In 1725 Van Imhoff entered into the service of the Dutch East India Company in Batavia (modern-day Jakarta), then colonial capital of the Dutch East Indies. Van Imhoff was promoted several times within the company before being appointed colonial governor in Ceylon (Modern-day Sri Lanka) on 23 July 1736.
Van Imhoff's tenure as governor of Ceylon put an end to the chaos that had pervaded the previous administration. He established constructive relations with Vira Narendra Sinha, King of Kandy.
King Narendra was married to a Tamil princess of Madurai (Tamil Nadu, India), and their child, Sri Vijaya Rajasinha who succeeded him after Narendra's death on 24 May 1739, was seen to be more of a Tamil than Sinhalese (the majority ethnic group in Ceylon). Van Imhoff was concerned about this royal succession as closer contacts between the Tamils of Ceylon (under King Sri Vijaya Rajasinha) and the Tamils of south India was seen as a threat to the Dutch East India Company's commercial monopoly. In his letters, Van Imhoff expressed his surprise that the Sinhalese people had accepted such a king, considering their haughty attitude towards the Tamils of India. However, Van Imhoff saw an interesting opportunity in this turn of events and proposed to the Lords Seventeen (Heeren XVII, the directors of the VOC) that the Kingdom of Ceylon be divided in two. They rejected the proposition as war was deemed as too costly.
Despite the profitable production of spices, the colony was always in a state of deficit because its profits were allotted to the VOC in general, not to the colony itself. This practice prevented the Governors from becoming too extravagant in their habits, as was the case in other colonies.