506th

506th may refer to:


 * 506th Air Expeditionary Group, provisional United States Air Force unit
 * 506th Air Refueling Squadron, inactive United States Air Force unit
 * 506th Airborne Infantry Regiment Association, charitable veterans' organization
 * 506th Bombardment Squadron, inactive United States Air Force unit
 * 506th Fighter Squadron, unit of the Oklahoma Air National Guard that flies the KC-135 Stratotanker
 * 506th Infantry Regiment (United States), unit assigned to the 4th Brigade Combat Team (BCT) of the 101st Airborne Division