| Oliver St Clair | |
| Baron of Roslin | |
| Predecessor: | William Sinclair, 11th Baron of Roslin |
| Successor: | William St Clair, 13th Baron of Roslin |
| Noble Family: | Clan Sinclair |
| Father: | William Sinclair |
| Mother: | Marjory Sutherland |
| Death Date: | 1523 |
Oliver St Clair (died 1523) was a Scottish noble and the 12th Baron of Roslin.
He was the eldest son of the second marriage of William Sinclair, 1st Earl of Caithness, 2nd Lord Sinclair and 11th Baron of Roslin to Marjory Sutherland, daughter of Sutherland of Duffus.[1] [2] His father had a son from his first marriage to Elizabeth Douglas, William Sinclair, 3rd Lord Sinclair, who although inherited the Lordship of Sinclair was apparently disinherited of the Barony of Roslin which went to Oliver and also of the earldom of Caithness which went to Oliver's younger brother, another William Sinclair.[1] [3]
On 9 September 1476 Oliver St Clair received from his father the baronies of Roslin, Pentland, and Pentland Muir, the barony of Herbertshire, the lands of Cousland, the barony of Ravenscraig, Dubbo, Carberry and Dysart. This was confirmed by charter from James III of Scotland on 10 September 1476. However, Oliver St Clair later gave to his brother, William Sinclair, 3rd Lord Sinclair who was also known as "of Newburgh", the lands of Cousland, Dysart and Ravenscraig with the castles in return for William and his son Henry renouncing their claims to the Barony of Roslin.[1] [4]
Oliver St Clair entered into a feud with Lord Borthwick which lasted for several years after St Clair threw one of the Borthwicks over the drawbridge at Roslin Castle after dinner.[1]
Oliver St Clair completed the construction of Rosslyn Chapel, which had been started by his father.[1]
Oliver St Clair was married firstly to Christian Haldane, secondly to Elizabeth, daughter of William Borthwick, 3rd Lord Borthwick, and thirdly to Isabella Livingstone. He had the following children:[1] [2]