A vice-county (vice county or biological vice-county) is a geographical division of the British Isles used for the purposes of biological recording and other scientific data-gathering. It is sometimes called a Watsonian vice-county as vice-counties were introduced for Great Britain, its offshore islands, and the Isle of Man, by Hewett Cottrell Watson who first used them in the third volume of his Cybele Britannica published in 1852. Watson's vice-counties were based on the ancient counties of Britain, but often subdividing these boundaries to create smaller, more uniform units, and considering exclaves to be part of the vice-county in which they locally lie.

A vice-county (vice county or biological vice-county) is a geographical division of the British Isles used for the purposes of biological recording and other scientific data-gathering. It is sometimes called a Watsonian vice-county as vice-counties were introduced for Great Britain, its offshore islands, and the Isle of Man, by Hewett Cottrell Watson who first used them in the third volume of his Cybele Britannica published in 1852. Watson's vice-counties were based on the ancient counties of Britain, but often subdividing these boundaries to create smaller, more uniform units, and considering exclaves to be part of the vice-county in which they locally lie.