Cognomen Siyavash (Siyavash 
) , across the world, is a very rare surname. The last name Siyavash is characteristic of Belgium, where it is a very rare surname, and Iran. More prevalently, Siyavash is the forename as well as the last name.
Rad, Diznab, Najafi, Noorin, Nejadi, Fiuzie, Kaynezhad, Rahmani, Gholami, Jabbari, Tehrani, Heydari, Mohajeri, Motealleh, Shahbazi, Ghorbani, Eslamizar, Fooladian, Siyavashi, Alvandimehr, Abdollahi, Mohandessi, Karimi, Moghtaderi, Bijani, Ahmadi, Teh, Mehr, Miri, Siya, Seif, Nili, Memar, Siami, Abedi, Azizi, Khial, Maleki, Mohebi, Moradi, Molaei, Mirzai, Saberi, Safari, Ansari, Araumi, Askari, Afshar, and Hosseinzadeh