First Battalion Four Marines
Personnel Rosters - Charlie Company
1 January - 31 December 1965
Tour Date - When Joined Company
| Name | Rank | MOS | Tour | Purple Heart | Purple Heart | KIA |
| Oberreiter, Orville W | PFC | 0311 | ||||
| O'Connell, Roderick D | L/Cpl | 0311 | ||||
| O'Connor, David L | L/Cpl | 0311 | ||||
| O'Connor, Jeremiah P, Jr | L/Cpl | 0331 | ||||
| Okon, Walter C | PFC | 0311 | ||||
| Olivares, Antonio | Sgt | 0311 | ||||
| Orfant, William J | Cpl | 0311 | 8 Aug 65 | |||
| Orozco, Richardo | PFC | 0311 | 1 Jun 65 | |||
| Osborne, Charles E | PFC | 0311 | ||||