Harry Stephen Harkness (July 17, 1880 – January 23, 1919) was an American racing driver, aviator, and playboy.

As a noted racer of the day, Harkness was retroactively awarded a 1902 American Automobile Association National Championship in 1951 by revisionist sportswriter Russ Catlin.

On March 4, 1911, he contracted early aviator Charles F. Walsh to build an airplane for use by his chief mechanic John Kiley at the Harkness camp established on North Island in San Diego, CA.

[2] According to at least one source, Walsh added "silver dust" to the unbleached muslin of the flying surfaces.

Harkness died of influenza in 1919, at his home, 270 Park Avenue, New York - four years following the death of his father.