The name Yarmouth appeared as the name of a projected township in Nova Scotia in a document in 1759, perhaps because it was the name of a favourite of George II. The same name was applied to a new county in 1836 when Yarmouth County was cut off from Shelburne County. The description of Yarmouth County was modified in 1846.
In 1856 Argyle was established as a separate district, with the District of Argyle comprising the Township of Argyle.