An olive drab disc 2 5/8 inches (6.67 cm) in diameter overall charged with a double quatrefoil horizontally divided into two equal halves red uppermost and blue, with a white center.
The double quatrefoil, which is a heraldic mark of cadency for the ninth son, has been made red and blue, the designating colors of an Infantry Division headquarters flag; the white center is in the color of the numerals for divisional flags.
The shoulder sleeve insignia was originally approved for the 9th Division on 18 November 1925. It was redesignated for the 9th Infantry Division effective 1 August 1942. The insignia was amended to revise the dimensions of the design to provide for an overedge stitching on 27 February 1970. (TIOH Dwg. No. A-1-85)