Shield
Or, a bar wavy Vert, overall on a saltire Gules a fleur-de-lis of the first fimbriated to chief and base of the third.
Crest
That for the regiments and separate battalions of the New York Army National Guard: On a wreath of the colors Or and Vert, the full rigged ship Half Moon all Proper.
Motto
VIGILANTIA ET VIS (Vigilance and Strength).
Shield
The colors yellow and green are for Armor. A fleur-de-lis on a red saltire, elements of the coat of arms of the 174th Infantry Regiment, indicates the organizations historic continuity with that unit and is symbolic of the Civil War and World War I campaign awards. The wavy band refers to the organizations home area, the vicinity of Buffalo, an important inland port.
Crest
The crest is that of the New York Army National Guard.
The coat of arms was originally approved for the 27th Reconnaissance Battalion on 5 August 1955. It was redesignated for the 121st Armor Regiment on 16 March 1962. The insignia was redesignated for the 121st Cavalry Regiment on 11 July 1967.