Shield
Gules, two lion's paws issuing out of the dexter and sinister base points chevron-ways Or.
Crest
On a wreath Or and Gules, a cannon barrel palewise Sable winged Argent behind a lion sejant affront with two heads addorsed of the first armed and langued Azure grasping in each forepaw a round of the third and surmounted by an escutcheon per pale Gules and of the fifth an annulet Argent, on a chief of the like three fleurs-de-lis Azure.
Motto
NOLI ME TANGERE (Don't Tread On Me).
Shield
The shield is scarlet for Artillery. The lion's paws are significant of Field Artillery, which may be likened to a mountain lion whose paw has great strength and power in felling and crushing a victim.
Crest
The lion with one head facing forward and the other backward, brandishing a round in both directions, refers to the organization's claim to have been the unit of the 101st Airborne Division to fire the first and the last rounds on German soil. The winged cannon stands for the former designation of the organization as a Glider Field Artillery Battalion and its assignment during World War II to the 101st Airborne Division. The red and blue escutcheon is from the arms of Bastogne; the annulet represents the enemy encirclement of that objective and refers to the unit's distinguished action in its defense during World War II. The three fleurs-de-lis stand for the organization's first war service, i.e., participation in three campaigns in France during World War I.
The coat of arms was originally approved for the 452d Field Artillery Regiment on 1 February 1927. It was redesignated for the 321st Field Artillery Regiment on 14 November 1930. It was redesignated for the 321st Field Artillery Battalion on 14 April 1942. It was redesignated for the 321st Glider Field Artillery Battalion on 14 October 1942. It was redesignated for the 518th Airborne Field Artillery Battalion and amended to delete the Organized Reserves crest on 26 September 1951. The insignia was redesignated for the 321st Airborne Field Artillery Battalion on 31 July 1956. On 25 February 1958, it was redesignated for the 321st Artillery Regiment. It was amended to add a crest on 22 April 1966. The insignia was redesignated for the 321st Field Artillery Regiment effective 1 September 1971.