| Alexander St Clair | |
| Baron of Roslin | |
| Predecessor: | James St Clair, 18th Baron of Roslin |
| Successor: | William St Clair of Roslin |
| Noble Family: | Clan Sinclair |
| Father: | James St Clair |
| Mother: | Jean Spotswood |
| Birth Date: | 1672 |
| Death Date: | 1706 |
Alexander St Clair (1672–1706) was the 19th Baron of Roslin.
He was the second son of James St Clair, 18th Baron of Roslin and Jean, daughter of Henry Spotswood, Sheriff of Dublin. His elder brother, James St Clair, had been killed fighting at the Battle of the Boyne in 1690 and therefore Alexander succeeded to the estates of Roslin.[1]
Alexander's poems are preserved in manuscript form in the Advocates Library.[1]
Alexander married Jean, daughter of Robert, 7th Lord Sempill. He was succeeded by his son, William St Clair of Roslin, and had two other sons and three daughters who died young.[1] Alexander died in 1706.[2]