Shield
Azure (Teal Blue), a volcano abase Argent surmounted by a pellet charged with a mullet of the second; in chief a lightning flash fesswise Tenn fimbriated of the second.
Crest
On a wreath of the colors Argent and Azure (Teal Blue), a demi-griffin Gules holding in its dexter claw a sword with blade in the form of a lightning flash Or all in front of a wreath of palm fronds Proper.
Motto
NEMO VIGILANTIOR (No One More Watchful).
Shield
Teal blue and white are the colors of Army Security Agency battalions and represent the former designation of the unit. The volcano symbolizes the area in the Pacific in which the unit served. The black sphere charged with a white mullet alludes to the coat of arms of Captain Cook who discovered New Caledonia, the island on which the unit was activated. The lightning flash refers to the mission of the unit and the orange color represents their former mission as a signal company.
Crest
The griffin, symbol of courage, strength and vigilance, represents the intelligence mission of the battalion. The unit's origin as a Signal Company is recalled by the lightning flash sword blade, which also denotes speed of response and action. The palm wreath refers to the battalion's Asiatic-Pacific service with distinction in World War II. Red signifies courage and recalls the award of the Meritorious Unit Citation to the battalion. Gold stands for excellence.
The coat of arms was originally approved for the 306th Army Security Agency Battalion on 30 April 1959. It was redesignated and amended to change the crest for the 306th Military Intelligence Battalion on 2 April 1991.