 Byrne was married (1835) in Paris to a Scots Presbyterian, Fanny Horner, (1789 - 1876) (originally from George Square, Edinburgh, Scotland) but they had no children.Fanny's father was John Horner, a "merchant of Edinburgh", and her mother was Joanna Baillie.They were married on Christmas Eve, 24 December 1835 in the British Embassy Chapel in Paris.