Colonel James Alexander Francis Humberston Stewart-Mackenzie, 1st Baron Seaforth, JP, DL (9 November 1847 – 3 March 1923) was a Scottish soldier, who was regarded by many as chief of Clan Mackenzie. Stewart-Mackenzie was the son of Keith William Stewart-Mackenzie (a son of James Alexander Stewart-Mackenzie) and Hannah Charlotte (daughter of James Joseph Hope-Vere). His sister became a society hostess and politician, known as Mary Jeune, Baroness St Helier. His grandmother was Mary Elizabeth Frederica Mackenzie, daughter and heiress of Francis Mackenzie, 1st Baron Seaforth, whose title had become extinct when his four sons all predeceased him.