Captain William John MacKenzie was an American flying ace who served with British naval aviation during World War I.

[1] He was working as a draftsman in Port Robinson, Ontario, Canada before joining the Royal Naval Air Service as a probationary Flight Sub-Lieutenant on 19 April 1917.

MacKenzie ended the war credited with eight confirmed aerial victories, having earned the Belgian Croix de Guerre and the Distinguished Flying Cross.

Mackenzie joined this squadron on 1 December 1917 and was employed in the Belgian Coast Patrol, where he distinguished himself by keen powers of observation and great enthusiasm for his work.

[2] "He returned to this squadron in October 1918 for the last push and displayed great gallantry and leadership in the many low bombing raids against enemy troops, etc.