O
This along with the †, indicates that the Medal of Honor was awarded posthumously
| Image | Name | Service | Rank | Place of action | Date of action | Notes |
|---|---|---|---|---|---|---|
| — | Obrien, William J.William J. O'Brien † | Army | O-05 !Lieutenant Colonel | Saipan, Marianas Islands | 01944-07-20June 20, 1944 – 01944-07-07July 7, 1944 | |
| Ocallahan, Joseph T.Joseph T. O'Callahan | Navy | Commander | near Kobe, Japan | 01945-03-19March 19, 1945 | Chaplain aboard aircraft carrier USS Franklin. | |
| — | Ogden, Carlos C.Carlos C. Ogden | Army | O-02 !First Lieutenant | near Fort du Roule, France | 01944-07-25June 25, 1944 | |
| Ohare, Edward H.Edward H. O'Hare | Navy | Lieutenant | off Papua New Guinea | 01942-03-20February 20, 1942 | O'Hare International Airport in Chicago was named in his memory. | |
| Ohata, Allan M.Allan M. Ohata † | Army | E-05 !Sergeant | near Cerasuolo, Italy | 01943-12-29November 29, 1943 – 01943-12-30November 30, 1943 | ||
| Okane, Richard H.Richard H. O'Kane | Navy | Commander | Philippine Islands | 01944-10-23October 23, 1944 – 01944-10-24October 24, 1944 | For submarine operations against two Japanese convoys. | |
| Okubo, James K.James K. Okubo † | Army | E-03 !Technician Fifth Grade | Foret Domaniale de Champ, near Biffontaine, France | 01944-10-28October 28, 1944 – 01944-10-29October 29, 1944 and 01944-12-04November 4, 1944 | ||
| Okutsu, YukioYukio Okutsu | Army | E-07 !Technical Sergeant | on Mount Belvedere, Italy | 01945-05-07April 7, 1945 | ||
| — | Olson, Arlo L.Arlo L. Olson † | Army | O-03 !Captain | crossing of the Volturno River, Italy | 01943-10-13October 13, 1943 | |
| — | Olson, Truman O.Truman O. Olson † | Army | E-05 !Sergeant | near Cisterna di Littoria, Italy | 01944-01-30January 30, 1944 – 01944-01-31January 31, 1944 | |
| Ono, Frank H.Frank H. Ono † | Army | E-02 !Private First Class | near Castellina, Italy | 01944-07-04July 4, 1944 | ||
| Oresko, NicholasNicholas Oresko | Army | E-08 !Master Sergeant | near Tettingen, Germany | 01945-01-23January 23, 1945 | For single-handedly destroying two bunkers while being seriously wounded. Currently the oldest living Medal of Honor recipient. | |
| Otani, KazuoKazuo Otani † | Army | E-06 !Staff Sergeant | near Pieve Di S. Luce, Italy | 01944-07-15July 15, 1944 | ||
| Owens, Robert A.Robert A. Owens † | Marine Corps | E-05 !Sergeant | Cape Torokina, Bougainville, Solomon Islands | 01943-12-01November 1, 1943 | ||
| Ozbourn, Joseph W.Joseph W. Ozbourn † | Marine Corps | E-01 !Private | Tinian Island, Marianas Islands | 01944-07-30July 30, 1944 | Private Ozbourn saved the lives of four fellow Marines by jumping on the top of a live hand grenade. |
Read more about this topic: List Of Medal Of Honor Recipients For World War II