All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The basic principle is that it is allowable for the man to let his hair grow long; however, it might sometimes be a source of Fitnah (temptation), as in the case of the questioner, so he should not let his hair grow long. Shaykh Ibn ‘Uthaymeen was asked, “Is it allowable for the man to let his hair grow long?”
He answered:
“If there is fear of potential Fitnah as is the case when the man is handsome and would be a source of Fitnah for others if he let his hair grow long, then we say: cut your hair and do not let it grow long. But if he is an average looking man and there is no fear of Fitnah, then the Sunnah is that he follows the custom of his country. If men in his country customarily let their hair grow long, then he does the same. If they customarily cut it short, then he does the same, because this is a custom, and it is better for the Muslim to abide by the common practice of his community as far as customary practices are concerned, unless they are prohibited by the Sharee'ah.” [Fataawa Noor ‘ala Ad-Darb]
This ruling applies to the man who is working as a model with greater reason. There is no doubt that such a profession is rarely free of Sharee'ah violations, as has previously been underlined in fatwa 86308.
Allaah knows best.