OPW
OPW is an abbreviation for:
- Obóz Polski Walczącej , ("Polish Combat Movement"), part of the Polish Home Army in World War II (1942–1944)
- Common Freight Car Park (Russian Общий парк вагонов (ОПВ), Obschtschi Park Wagonow), sub-organization of the Council for Mutual Economic Aid (Comecon) (1964–1990)
- Office of Public Works , subordinate to the Treasury of the Republic of Ireland for the administration of Ireland's historical heritage and public works