Is it permissible to withdraw from a marriage contract that was concluded after the suitor saw the fiancée without a head covering and found her unattractive, given that she refused to uncover her head during the engagement?

There is no sin in the betrothed woman refusing to uncover her head, as the majority opinion is that what is permissible to look at does not exceed the face and the hands. It is not permissible to annul the marriage merely because she did not uncover her head, for you contracted the marriage willingly, and you could have requested to see her head through one of your Mahrams. And generally, a woman's beauty lies in her face, which you have seen.

If you cannot tolerate her, you are permitted to divorce her, but it is advised not to rush into it, based on the Prophet's (peace be upon him) saying: "A believing man should not hate a believing woman; if he dislikes one of her characteristics, he will be pleased with another."

If you know that you cannot tolerate this, and you fear wronging her or falling short in her rights, then divorce her. Divorce before consummation and having children is less harmful, and it is a remedy for an unbearable cohabitation.

It is advised to perform Istikhara (prayer for guidance) before proceeding with divorce.