Surname אוסלר (Osler 
, Uslar 
, אוסלר 
) , in the world, is quite a rare family name. The surname אוסלר is habitual in Lesotho, where it is quite a rare surname, Bolivia, and Nicaragua, where it is a rare surname. In absolute terms, it most frequently occurs in the United States, the United Kingdom, and Italy. Much less frequently, אוסלר is the forename as well as the last name.