The name of Seaforth is thought to come from the Old Norse "sæ-fjord", "sæ-ford", "sea inlet". It was recorded as "Safforde" "sea ford" in 1128, suggesting Old English name origins. Another theory for the name of the area is that it was taken from Seaforth House, named after Francis Mackenzie, 1st Baron Seaforth, who built the mansion in 1813 for his daughter and her husband, Sir John Gladstone, father of William Ewart Gladstone, four times Prime Minister of the United Kingdom.