| O'Shea | J | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Cape Medical Staff |
| O'Sullivan | T | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Cape Mounted Riflemen |
| O'Toole | J | | Captain | CGHGSM (1) Basutoland
Source: Roll of the CGHGSM | Field Force |
| Oakley | E R | | Private | CGHGSM (1) Basutoland
Source: Roll of the CGHGSM | Dymes Rifles |
| Oates | C H | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Cape Police |
| Ockenden | O G | | Sergeant | CGHGSM (1) Basutoland
Source: Roll of the CGHGSM | Cape Mounted Riflemen |
| Oelschig | J H | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Cape Police |
| Officer | W | | Captain | CGHGSM (1) Basutoland
Source: Roll of the CGHGSM | Colesberg Burghers |
| Ogilvie | G W | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Kaffrarian Rifles |
| Okes | H T | | Private | CGHGSM (1) Bechuanaland. CPD2
Source: Roll of the CGHGSM | Cape Police |
| Oldridge | F W | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Kimberley Rifles |
| Olifant | Jacob | 1147 | | CGHGSM (1) Bechuanaland. CPD1. Native Private
Source: Roll of the CGHGSM | Cape Police |
| Olifant | T | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | Kimberley Rifles |
| Oliver | H T B | | Private | CGHGSM (2) Basutoland Transkei
Source: Roll of the CGHGSM | Cape Mounted Yeomanry |
| Oliver | W E | | Corporal | CGHGSM (1) Basutoland
Source: Roll of the CGHGSM | Kimberley Horse |
| Olivier | J S | | Private | CGHGSM (1) Transkei
Source: Roll of the CGHGSM | Oudtshoorn Burghers |
| Ollett | J T | | Private | CGHGSM (1) Basutoland
Source: Roll of the CGHGSM | Cape Mounted Riflemen |
| Ollett | R R | | Sergeant | CGHGSM (1) Transkei
Source: Roll of the CGHGSM | George Burghers |
| Olyott | J W | | Private | CGHGSM (1) Bechuanaland
Source: Roll of the CGHGSM | First City Volunteers |
| Oosthuizen | G I | | Sergeant | CGHGSM (1) Transkei
Source: Roll of the CGHGSM | Alexandria Burghers |
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