Shield
Argent, on a bend Azure voided of the field, between in chief a double warded key bendwise, wards downward and issuant from base a tower Sable, lighted Gris (Grebe Gray), a lightning bolt Gules.
Crest
From a wreath Argent and Azure, between a pair of wings Or, five arrows four Proper, one of the third, arrowhead Gules, bound together by two ribbons of the last, the second ribbon garnished Vert.
Motto
FIRMUS VIGILO VALIDUS (Reliable, Vigilant and Strong).
Shield
The white bend, edged blue signifies the Third Brigade Combat Team's vigilance to protect national defense. The combined symbols within the coat of arms form the Special Troops Battalion the tower denotes the Engineer element; the key indicates the Military Intelligence role and the Military Police functions, and the lightning bolt alludes to Signal.
Crest
The wings denote the Third Brigade Combat Team's mission. The four arrows symbolize the unit campaign participation World War I, World War II, Armed Forces Expeditions, and Southwest Asia. The middle arrow highlights the Brigade's duty in Vietnam. The red and yellow colors refer to the unit's decoration of the Vietnam Cross of Gallantry; the red of the band denotes the Meritorious Unit Commendation and the red/green suggests the Republic of Vietnam Civil Actions Medal.
The coat of arms was approved on 13 April 2007.