Shield
Or, a tilting spear in bend Vert, between a horse's head couped and a gauntlet of the like, all within a bordure of the second.
Crest
That for the regiments and separate battalions of the California Army National Guard: On a wreath of the colors Or and Vert, the setting sun behind a grizzly bear passant on a grassy field all Proper.
Motto
VELOX ET MORTIFER (Swift and Deadly).
Shield
The shield of the coat of arms for the 111th Armored Cavalry Regiment, differenced by a green border, indicates descent of the 139th Tank Battalion from the 3d Battalion of that organization. The colors yellow and green are used for Armor. The horse's head and lance symbolize Cavalry and medieval armor, respectively. The gauntlet represents the shock action of armor and the ability to deliver a decisive blow.
Crest
The crest is that of the California Army National Guard.
The coat of arms was originally approved for the 139th Tank Battalion on 28 February 1956. It was redesignated for the 18th Armored Cavalry Regiment on 24 April 1968. The insignia was redesignated for the 18th Cavalry Regiment on 13 May 1975.