Surname Caol (Kyle 
, Caol 
, Каору 
) , all over the world, is a common cognomen. The cognomen Caol is habitual in British Virgin Islands, where it is quite a common surname, Jersey, and Reunion. In absolute terms, it is commonest in the United States, the United Kingdom, and Canada. More prevalently, Caol is the forename as well as the last name.