James Hardy Marks, DSO & Bar, DFC (19 March 1918 – 20 September 1942) was an officer in the Royal Air Force. An early proponent of developing a target marking method, he was the commanding officer of 35 Squadron when it was selected as one of the five founding squadrons of the Pathfinder Force. He was considered by his contemporaries as one of the top aviators of his time. He was killed while returning from a raid against Saarbrücken when his Halifax was set afire from an attack from a German night fighter. Marks stayed at the controls to allow his crew to escape before his aircraft crashed near Blesme in northern France.