Is it permissible for a woman to complete her studies in a non-Muslim country with the intention of utilizing her time and seeking beneficial knowledge, if it requires her to study in mixed-gender classes while maintaining her lawful hijab, knowing that her husband objects to it due to the mixing?

Obeying the husband is obligatory, especially concerning his commands regarding obedience [to Allah] or his prohibitions regarding disobedience [to Allah]. The wife has been promised a great reward for her obedience to her husband, as indicated by the Prophet's (peace be upon him) saying: "If a woman prays her five [daily prayers], fasts her month [of Ramadan], guards her chastity, and obeys her husband, it will be said to her: 'Enter Paradise through whichever of its gates you wish.'" What your husband has commanded you to do is what must be done, because the mixing of men and women in education and work is forbidden.

A woman's study and pursuit of knowledge are permissible; what is forbidden is mixing, unveiling, and apparent and hidden sins in educational environments. A woman must learn what is necessary to rectify her religious affairs, and she may go out to an institute or school if learning without going out is not possible for her. The Permanent Committee has stated that a woman's study of religious and other sciences is permissible if it does not lead to a forbidden outcome, such as mixing with non-mahram men or not observing hijab.

The mixing of men and women in education is forbidden and a grave evil, due to the temptation it entails and the spread of corruption, especially if it is in the lands of the disbelievers. A woman's learning is not among the necessities that permit forbidden acts.

Therefore, obey your husband in refraining from mixed-gender education, and be patient until you return to your country. Utilize your time in seeking knowledge by listening and reading, and exert effort with Muslim women of your gender in education and guidance, and with disbelieving women in da'wah and guidance.