Hadith: If any woman marries without the permission of her guardians, her marriage is void

عن عائشة رضي الله عنها مرفوعًا: «أيُّما امرأةِ نَكَحَت بغير إذن مَواليها، فنِكاحها باطل»، ثلاث مرات «فإن دخلَ بها فالمهرُ لها بما أصاب منها، فإن تَشاجروا فالسلطان وَلِيُّ مَنْ لا وَلِيَّ له».
[صحيح] - [رواه أبو داود والترمذي وابن ماجه والدارمي وأحمد]

‘Ā’ishah (may Allah be pleased with her) reported that the Prophet (may Allah's peace and blessings be upon him) said: "If any woman marries without the permission of her guardians, her marriage is void," repeating it three times, "and if the marriage is consummated, she shall be entitled to the dowry in return for his copulation with her. If a dispute arises between them, the ruler shall be the guardian of whoever has no guardian."
Sahih/Authentic. - [Ibn Maajah]

Explanation

In this Hadīth, the Prophet (may Allah's peace and blessings be upon him) stipulated the consent of a woman’s guardian for the validity of marriage, stating that if a woman were to marry someone without the permission of her guardian, entering into the marriage contract on her own, her marriage shall be void. Moreover, if marriage is consummated, the two of them shall be separated and the woman is entitled to the dowry on account of the intercourse. Then the Prophet (may Allah's peace and blessings be upon him) clarified that in case the guardians differ with regard to the woman’s marriage, or the woman disagrees with her guardians, her affair shall be left to the ruler, who is regarded as the guardian of anyone having no guardian.