Cognomen Séanna (Seanna 
, Séanna) , all over the world, is a very rare surname. The cognomen Séanna is characteristic of Indonesia, where it is a very rare surname, Canada, where it is an extremely rare surname, and Venezuela. Measured by absolute frequency, it is commonest in Indonesia, the United States, and Canada. Much more frequently, Séanna is the forename as well as the last name.