Camp Adair had two divisional headquarters buildings, one for each Army division that trained on the post, as well as a headquarters building for the Ninth Service Command located near the warehouse district. These headquarters served as the administrative centers where military operations, personnel records, and daily activities were coordinated.

The headquarters area also included the post Provost Marshal's Office,  and the  commander was Captain Hale Julius, which was responsible for military law enforcement, security, traffic control, and the administration of the post stockade. Nearby were several American Red Cross (ARC) buildings, where staff and volunteers provided assistance to soldiers and their families through emergency communications, recreation, counseling, and other support services.

Camp Adair also contained several finance buildings. The largest finance office belonged to the Ninth Service Command, where military payrolls were processed before funds were distributed to the finance offices serving each division. Soldiers could also conduct banking business at the post bank, located on Service Club Avenue opposite the small theater and between the guest houses, plus the bus station with PX 1 and 2.

Today, visitors can still see the remaining foundation of one of Camp Adair's finance buildings in the center of the Memorial Gardens, providing a visible reminder of the post's wartime administrative operations.