The Commanding Officer of an infantry battalion was an officer holding the rank of Lieutenant Colonel. An officer of a lower rank, in certain circumstances, could also command the battalion and he may or may not have been temporarily promoted to Lieutenant Colonel rank while so employed. The 15th Battalion had five Commanding Officers over the period 1914-1919:
- LCol JA Currie (top left/#2) September 1914 to April 1915
- LCol WR Marshall (top centre/#1) April 1915 to May 1916 (Killed in action)
- LCol CE Bent (top right/#3) May 1916 to May 1919
- Maj JP Girvan 1918 (Bottom left/#4)
- Maj JW Forbes 1917-1918 (Bottom right/#5)
Majors Girvan and Forbes both commanded for periods of time when Lieutenant Colonel CE Bent was away from the battalion and, while so employed, were temporarily promoted to the rank of Lieutenant Colonel.