Sepandiār or Esfandiyār was a legendary Iranian hero, also known as Belfian. He was the son and the crown prince of the Kayanian King Goshtasp and brother of the saintly Pashotan.

The "Sepandiār" is best known as the legend for the tragic story of a battle with Rostam, as described in Ferdowsi's epic Shahnameh (Book of Kings). It is one of the longest episodes in Shahnameh, and one of its literary highlights.