Ian presumably lived in England with his wife, whom he was unaware was a witch. They had three daughters together and many of his grandchildren and great-grandchildren lived in the United States. It is unknown if he is still alive or not; Gillian Lennox, one of his great granddaughters, recalls Elspeth but not Ian, possibly suggesting he is deceased. All of Ian's daughters were lost witches who passed their witch genes onto their children and grandchildren. Some of his most prominent descendants include Gillian Lennox and Iliana Dominick, the Witch Child.
Ian is the Scottish Gaelic form of John, which is derived Hebrew meaning "God is gracious" or "the grace/mercy of the Lord".
Kennedy is thought to be the Anglicized form of the Gaelic Ceannéidigh, meaning "ugly head" or "helmeted head".
- The family tree implies that Gisele is a descendant of Ian's through Mary; however this appears to be an error, as Gisele is never mentioned as being a Harman and because Mary should actually be the grandmother of Iliana, who on the tree is listed as a descendant of Emmeth Harman, but is stated in the novels to be a descendant of Elspeth.
- The tree further implies that Ian is the father of Grandin Harman, the father of Sylvia Weald. However, this would make Sylvia a lost witch, which information in the novels does not seem to support. Also, Grandin would then be known as Grandin Kennedy, not Harman, as witches are matriarchal and take their mothers' surnames.