Cognomen สีหราช (สีหราช 
, Siharaj 
, Siharat ) , throughout the world, is quite a rare surname. The last name สีหราช is characteristic of Laos, where it is quite a rare surname, Thailand, and France, where it is a very rare surname. Measured by absolute frequency, it most frequently occurs in Thailand, Laos, and the United States. Likewise, สีหราช is the forename as well as the last name.