398th

398th may refer to:

398th Air Expeditionary Group, provisional United States Air Force unit assigned to the United States Air Forces in Europe 398th Bombardment Squadron, inactive United States Air Force unit last assigned with the 92d Operations Group at Fairchild Air Force Base, Washington 398th Fighter-Interceptor Squadron, inactive United States Air Force unit, last assigned to the Air Defense Command stationed at Hamilton AFB, California

See also 398 (number) 398, the year 398 (CCCXCVIII) of the Julian calendar 398 BC