| O |
 |
| Oboe |
Code
name for British radio-navigational aid used by
RAF bombers |
| Octagon |
Code
name for the second Quebec conference between
Roosevelt and Churchill - September 1944 |
| OFEC |
Office
of Foreign and Economic Co-ordination (USA) |
| Oflag |
Offizier-Lager
- "Officer Camp" German prisoner-of-war camps
for Allied officers |
| OKH |
Oberkommando
der Heeres - High Command of the German Army |
| OKL |
Oberkommando
der Luftwaffe - High Command of the German Air
Force |
| OKM |
Oberkommando
der Kriegsmarine - High Command of the German
Navy |
| OKW |
Oberkommando
der Wehrmacht - High Command of the German Armed
Forces |
| Olive |
Operational
code name for the Allied assault on the Gothic
Line, Italy - August 1944 |
| Omaha |
Code
name for one of the US Normandy beach landing
areas used on D-Day,
the site was between Coleville and Vierville |
| OPD |
Operations
Division of the US Department of War |
| OSS |
Office
of Strategic Services - US military intelligence
and special operations agency |
| Overlord |
Operational
code name for Allied operations in Normandy and
North West Europe, beginning with Operation Neptune
on D-Day, 6th June
1944. |
| OWI |
Office
of War Information (USA) |
