Surname Caolán (Caolán 
) , in the world, is an extremely rare cognomen. Much more prevalently, Caolán is the forename as well as the last name.
Daly, Harvey, Harkin, Hargan, O'Kane, Maguire, Mc Cabe, Mc Aree, Mcgarry, Mckeown, Mcmanus, Carroll, Bradley, Doherty, Gormley, O'Dwyer, Mcdonald, Johnston, Thompson, O'Reilly, Mccallion, O'Donnell, Gordon, Deehy-Power, Devlin, Devine, Egan, Ward, Smith, Carty, Brady, Kelly, Roche, Doran, Doyle, Duffy, Winterson, Lynch, Owens, Walsh, Quinn, Scully, Carson, Colton, Curran, Bergin, Kearns, Reilly, Irwin, and Mclaughlin