 The Commandant of the United States Marine Corps is the highest @-@ ranking officer of the United States Marine Corps and a member of the Joint Chiefs of Staff , reporting to the Secretary of the Navy but not to the Chief of Naval Operations . Three Marines who served in 2nd Battalion 9th Marines became Commandant of the Marine Corps . They are listed in the table in accordance to the years in which they served as <unk> and their ranks are those which they held while serving in 2 / 9 , they were : 
