Last name オブライエン (O'Brien 
, O'Brian , オブライエン 
) , around the globe, is a common family name. The cognomen オブライエン is characteristic of Ireland, where it is a common surname, Australia, where it is quite a common surname, and Jersey (explore the name in all countries). Measured by absolute frequency, it most frequently occurs in the United States, Australia, and Ireland. Very seldom, オブライエン is the forename as well as the last name.