Cognomen Сельджук (Seljuk 
, Seldjouk 
, Сельджук 
) , across the world, is a very rare family name. The last name Сельджук is characteristic of Belarus, where it is a rare surname, Austria, and Germany, where it is an extremely rare surname. Not in comparison with a country's population, this name is the most popular in Belarus, Austria, and the United States. Much less frequently, Сельджук is the forename as well as the last name.