Azure, four fleurs-de-lis palewise in bend between in sinister chief a Spanish castle and dexter base a prickly pear cactus, all Or.
That for the regiments and separate battalions of the Illinois Army National Guard: From a wreath Or and Azure, upon a grassy field the blockhouse of old Fort Dearborn Proper.
PRO MAIORE SECURITATE (For Greater Security).
The service of the former organization, the 129th Infantry, is indicated by the blue shield which represents Infantry. The Spanish castle and cactus represent the Spanish-American War and Mexican Border service, respectively, while the four fleurs-de-lis are for the World War I honors of the organization.
The crest is that of the Illinois Army National Guard.
The coat of arms was originally approved for the 129th Infantry Regiment on 20 June 1933. The insignia was redesignated for the 129th Regiment, with the blazon and symbolism revised, on 21 May 1997.