ADSEC, officially the Advance Section of the Communications Zone, was a military logistics unit active in the Second World War.

The Com-Z also comprised the Delta Base and Continental Advance Section (CONAD) coming from southern France in support of the Sixth United States Army Group.

Besides staging supplies for the advancing armies to be sustained by ADSEC, the Com-Z also rehabilitated railway rolling stock, restoring rail operations to ever-more forward bases, and provided transportation of food, ordnance, and POL (Petroleum, Oil and Lubricants) using motor operations (see Red Ball Express).

Its engineering activities included managing the beaches and building artificial ports before handing control of the area to Com-Z units.

Eventually the Com-Z and ADSEC were supporting all three northwest Europe U.S. combat armies (1st, 3rd, & 9th) moving across France and into Belgium, Holland and Germany.

At the end of hostilities, ADSEC was close at hand in central and eastern Germany, and sustained the Allied armies as they settled in for occupation duty.