| Collection | Reference |
| Ogilvie (James), Deputy Commisary General |
MSS.15201-15335 |
| Ogilvie (Iain Hamish), Civil Engineer |
Acc.11851 |
| Ogilvie (William H. ), Author and Journalist |
MSS.26027-26029 |
| Ogilvie of Barras Papers |
MS.2051 |
| Ogilvie of Boyne Papers |
MSS.21248-21249 |
| Ogilvy (David), Merchant, Leith |
Acc.12526 |
| Ogilvy of Bennachy |
Acc.9322 |
| Ogilvy of Innerquharity Papers |
Acc.5012 |
| Ogleface Friendly Society |
Acc.3826 |
| Ogscastle deeds |
Acc.5621 |
| Oliphant (Margaret Oliphant Wilson), Novelist |
Acc.13098 |
| Oliphant (Margaret Oliphant Wilson), Novelist |
Acc.13240 |
| Oliphant (Margaret Oliphant Wilson), Novelist |
MSS.23193-23208 |
| Oliphant of Gask Papers |
Adv.MSS 82.1.1-82.9.13 |
| Oliver (A. M.), Miss |
Acc.9437 |
| Oliver (Frederick Scott) |
MSS.24781-25100 |
| Oliver (George), Emigrant |
Acc.13019 |
| Oliver (George), Emigrant |
Acc.13020 |
| Oliver (John W.), Dr. |
Acc.9120 |
| Oliver (Peter Roderick), Lieutenant-Colonel |
Acc.12096 |
| Oliver (Peter Roderick), Lieutenant-Colonel |
Acc.13124 |
| Oliver (Peter Roderick), Lieutenant-Colonel |
MSS.24656-24720 |
| Oliver and Boyd, Publishers, Edinburgh |
Acc.5000 |
| O'Neil (Felix), Captain, Officer of Prince Charles Edward |
Acc.5491 |
| Operative Plumbers' Association of Great Britain and Ireland: Edinburgh Lodge |
Acc.4961 |
| Order for the Glencoe Massacre |
Adv.MS.23.6.24 |
| Order of the Garter |
Adv.MS. 31.7.18 |
| Order of the Garter |
Adv.MS.32.6.9 |
| Order of the Garter |
Ch.A.43 |
| Order of the Garter |
MS.7143 |
| Order of the Thistle |
Adv.MS 34.6.2 |
| Order of the Thistle |
Adv.MS.31.1.13 |
| Orr (Bob) |
Acc.12766 |
| Orr (John Boyd), Baron Boyd Orr |
Acc.6545 |
| Orr (Robin Kemsley), Composer |
Acc.10462 |
| Orr (Robin Kemsley), Composer |
Acc.10598 |
| Orr (Robin Kemsley), Composer |
Acc.10670 |
| Orr (Robin Kemsley), Composer |
Acc.10723 |
| Oswald (Henry Robert), Surgeon-General, India |
Ch.8431-8434 |
| Oswald (Henry Robert), Surgeon-General, India |
MSS.9001-9042 |
| Ouseley Family |
MSS.21209-21213 |
| Owens (Agnes), Novelist |
Acc.12938 |
| Owens (Agnes), Novelist |
Acc.8822 |
