Fayruz al-Daylami (Arabic: فيروز الديلمي) was a Persian companion of the Islamic prophet Muhammad. He belonged to the descendants of Persians that had been sent by Khusraw Anooshiravan to Yemen, conquered it, and drove out the Abyssinians.
He was sent out by Muhammad to assassinate Aswad Ansi, who had claimed prophethood in Yemen. In reference to this, Muhammad was reported as saying, "He was killed by the virtuous man Fayruz b. al-Daylami." Fayruz died during the caliphate of Uthman.