Rear Admiral John Denison (1853 – March 6, 1939) was a Canadian member of the Royal Navy.
His great-grandfather, grandfather, father, and five brothers served as army officers, but Denison joined the Navy in 1867, as a midshipman. From 1893 to 1896 he commanded the royal yacht Victoria and Albert II and has been described as the first Canadian to command a fleet.
He served as naval aide de camp to King Edward VII from 1905 to 1906.
Denison was promoted to Rear Admiral on 18 September, 1906.
He was promoted to Vice Admiral on 10 February 1911.
He was promoted to Admiral on 7 December 1913 and was placed on the Retired List on 8 December
Denison died in Alverstoke on March 9 1939.