A Gold color metal and enamel device 1 5/32 inches (2.94 cm) in height overall consisting of a shield blazoned: Per chevron Or and Gules, on a pale counterchanged between in chief two fleurs-de-lis of the second a castle in base Azure. Attached below and to the sides of the shield a Gold scroll inscribed "EVER ON CALL" in Red letters.
A chevron symbolizes support, the chief mission of Artillery and the pale signifies strength; together they indicate "support with strength". The red divisions of the shield represent the batteries of the Regiment and allude to "fire power". The yellow divisions symbolize the three periods of combat services of the unit. The castle from the Spanish flag represents Manila and is for the Philippine Insurrection. The Infantry color, blue, is used to denote the unit was originally constituted as Infantry and served as such in the campaign. Blue and red are the colors of the Philippine Insurrection ribbon. The two fleurs-de-lis represent service in Europe during World War I and World War II and are red to indicate Artillery.
The distinctive unit insignia was originally approved for the 115th Field Artillery Battalion on 27 December 1951. It was redesignated for the 115th Armored Field Artillery Battalion on 30 June 1955. On 13 October 1960, it was redesignated for the 115th Artillery Regiment. The insignia was redesignated for the 115th Field Artillery Regiment on 28 July 1972.