Fiske graduated from the U.S. Naval Academy in 1874. As the navigator of the gunboat Petrel, he used one of his inventions, a stadimeter range finder, to communicate the ranges of enemy ships to American gunners during the Battle of Manila Bay (1898). He eventually rose to the command of cruiser and battleship divisions, reaching the rank of rear admiral in 1911.

Fiske was probably the greatest naval inventor of his time, with numerous innovations in electrical and gun-control systems to his credit from the mid-1870s on. Chief among his inventions were an electric range finder, electric ammunition hoists and gun-turret motors, a naval telescope mount and sight, radio systems for the control of torpedoes, and electrical control systems that kept naval batteries aimed at their targets while firing continuously.

Fiske resigned from the U.S. Navy in 1915, after years of policy disputes with department officials over the need for a naval general staff in order to ensure adequate military preparation. Besides the creation of the latter in 1915 as the Office of the Chief of Naval Operations, Fiske saw many of his inventions developed and used successfully in World Wars I and II. He wrote From Midshipman to Rear-Admiral (1919), an account of his experiences in the U.S. Navy.