Rear-Admiral Captain John Bowker was a British Naval officer and Governor of Newfoundland from 24 February 1818 to 19 July 1818. As a senior officer under Francis Pickmore, Bowker was appointed Governor following his death. On 3 August 1785, Bowker joined the Royal Navy.
Bowker was the Flag-Captain aboard the HMS Sir Francis Drake.
On 31 July 1844, he was made Captain of Greenwich Hospital.