Cognomen Hadjaev (Хаджаев 
, Hadjaev 
, Хадйаев ) , throughout the world, is a rare last name. The surname Hadjaev is habitual in Azerbaijan, where it is quite a rare surname, Kyrgyzstan, where it is a rare surname, and Kazakhstan. In absolute terms, it is the most numerous in Russia, Kazakhstan, and Azerbaijan. Much less frequently, Hadjaev is the forename as well as the last name.