Ko te 504th Infantry Regiment, i te tuatahi ko te 504th Parachute Infantry Regiment (504th PIR), he ope rererangi rererangi o te United States Army, he waahanga o te 82nd Airborne Division, me te hitori roa me te rongonui. I whakatuhia te roopu i waenganui o te 1942 i te Pakanga Tuarua o te Ao hei waahanga o te 82nd Airborne Division ka kite i te mahi i Sicily, Itari, Anzio, Netherlands
, Belgium me Germany.