Born James Alexander Stewart, the son of Vice Admiral Keith Stewart (who died when James was eleven), he assumed the surname Stewart-Mackenzie after his marriage on 21 May 1817 to Mary Elizabeth Frederica Mackenzie ("the Hooded Lassie"), daughter of Francis Mackenzie, 1st Baron Seaforth.
Stewart-Mackenzie was elected to the House of Commons as Member of Parliament for Ross-shire in 1831. When that constituency was abolished in 1832, he was elected for the new Ross and Cromarty, serving until 1837.
He sold the house and grounds of Woodfall Gardens, Glasserton in 1819 to Stair Hathorn-Stewart at the neighboring Physgill estate.
His daughter was Louisa Caroline Stewart-Mackenzie.
|7th Governor of British Ceylon|
7 November 1837 – 15 April 1841
|Preceded by||Robert Wilmot-Horton|
|Succeeded by||Colin Campbell|
|Born||23 September 1784|
|Died||24 September 1843 (aged 59)|
|Parliament of the United Kingdom|
Sir James Wemyss Mackenzie
| Member of Parliament for Ross-shire
|New constituency|| Member of Parliament for Ross and Cromarty
| Governor of Ceylon