Description
An olive drab disc 2 5/8 inches (6.67cm) in diameter overall charged with a double quatrefoil horizontally divided into two equal halves red uppermost and blue, with a white center.

Symbolism
The double quatrefoil, which is an 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.

Background
The shoulder sleeve insignia was originally approved for the 9th Division on 18 Nov 1925. It was redesignated for the 9th Infantry Division on 1 Aug 1942. On 27 Feb 1970 the description was amended to revise the dimensions of the design. (TIOH Dwg. No. A-1-85)