Orange and white, branch colors of the Signal Corps, are used almost exclusively in the design of the 9th Signal Battalion Distinctive Unit Insignia, commonly called a unit crest. This insignia was originally approved while the Battalion was still designated as the 9th Signal Company; on it, the crossed wing foot and bolt of lightning refer to the swiftness of communications handled by the unit, which was inactivated at Fort Lewis in Washington on 15 July 1991.

Although the 9th Signal Battalion can trace its history back to the constitution of the 209th Field Signal Battalion in the Regular Army on 8 July 1918, the unit did not see action until World War II—and from its record it would appear it was attempting to make up for lost time. Designated as the 9th Signal Company and assigned to the 9th Infantry Division, the unit took part in no fewer than eight campaigns in the European–African–Middle Eastern theater, earning an Arrowhead device for taking part in an assault landing in the Algeria-French Morocco campaign. Its outstanding service was also recognized with a Presidential Unit Citation, a Meritorious Unit Citation, and the Belgian Fourragere 1940, with two Citations in the Order of the Day of the Belgian (Meuse River and Ardennes).