Surname Ослер (Osler 
, Ослер 
) , in all the world, is quite a rare cognomen. The cognomen Ослер is habitual in Lesotho, where it is quite a rare surname, Nicaragua, where it is a rare surname, and Canada. Measured by absolute frequency, this name is the most popular in the United States, the United Kingdom, and Italy. Very seldom, Ослер is the forename as well as the last name.