Hijab and chastity are not merely a religious commandment and a legal duty for Muslim women; rather, they are among the social necessities of human societies. Their presence brings profound benefits and impacts to society, while their non-observance leaves devastating damages and effects on the public culture of society and the family system. Under the shelter of preserving this value, a woman can be a powerful factor in maintaining healthy social relations and human and spiritual values. Hijab and clothing are not unprecedented in religions and pre-Islamic nations, and it is certain that hijab existed before Islam among nations, even among the people of ancient Iran. Just as Islam has forbidden wine and other prohibitions due to the corruptions inherent in those sins, it has also forbidden lack of hijab due to its various corruptions. Islam desires women to have dignity, and when they appear in society, they should do so as human beings rather than as the opposite sex to men. Both men and women are primarily human beings, and both must appear in the social environment and interact in a way that does not pollute or contaminate society. The Muslim woman is the embodiment of sanctity and chastity in society; maintaining coverage and hijab is a form of respecting women and protecting them from lustful gazes. This paper briefly examines the history of hijab, women's attire in Islamic culture, the dimensions of hijab in the Holy Quran, the wisdom and philosophies of hijab and chastity, the effects of hijab in ensuring individual and social security especially for women, the issue of hijab from the perspective of the Supreme Leader of the Islamic Revolution, and concludes by offering suggestions for promoting Islamic hijab.