bismi-llahi r-raḥmani r-raḥīm,
Assalamu ‘laikum warahmatullahi wabarakatuh,
All praise and thanks are due to Allah (سبحانه و تعالى), and peace and blessings be upon His Messenger (صلى الله عليه و سلم).
Dear questioner,
First of all, we implore Allah (سبحانه و تعالى) to help us serve His cause and render our work for His sake.
Shorter Answer: It is absolutely permissible for a younger man to marry an older woman in Islam. However, both traditionally and contemporarily, a typical marriage involves an older man and a younger woman. These norms of course, change based on both common practice and common law. The focus here is on the inherent sex differences in resources that men and women bring to relationships. Consequently, most men preferred younger, physically attractive women, while most women, of any age, preferred successful, established men their age or older.
Long Answer: From the fatwa of Shaykh Ibn Baaz in Fataawa Islamiyyah, it is clear that “age does not matter, and it does not matter if the woman is older or if the husband is older. The Prophet (صلى الله عليه و سلم) married Khadeejah (رضي الله عنها) when she was forty and he was twenty-five. What does matter is that the man should look for a righteous woman who is religiously-committed, even if she is older than him, if she is still young enough to bear children. The point is that age should not be a problem and such a marriage is not wrong if the man is righteous and the woman is righteous.”
