Surname Каарло (Kaarlo 
, Каарло 
) , in the entire world, is a very rare last name. The last name Каарло is habitual in Finland, where it is a rare surname, Spain, where it is a very rare surname, and Venezuela, where it is an extremely rare surname. In absolute terms, it is commonest in Finland, China, and Spain. Much more frequently, Каарло is the forename as well as the last name.