A gold color metal and enamel device 1 1/8 inches (2.86 cm) in width overall consisting of a blue triangular area surmounted by a gold semi-sunburst with six full points, at the top a gold demi-fleur-de-lis between a background of Philippine sun rays, in base a blue Torii gate behind a vertical red arrowhead (point up, and extending slightly in front of the sunburst), all above a circular gold scroll inscribed "DUTY HONOR COURAGE" in red letters.
The semi-sunburst was suggested by the unit's shoulder sleeve insignia and represents the Division's allocation to the State of California. The demi-fleur-de-lis symbolizes service in World War I. The outer rim of sun rays refers to the Philippine Presidential Unit Citation award. The red arrowhead alludes to the fire power of the unit and represents their assault landing at Luzon in World War II. The Torii gate, a symbol of the Far East, refers to the awarded Republic of Korea Presidential Unit Citation.
The distinctive unit insignia was originally approved for the 40th Infantry Brigade on 13 January 1970. It was redesignated for the 40th Infantry Division on 31 January 1974.