Short answer
Yes, you can attend a family member's or friend's wedding to keep ties, and you may congratulate the couple on their marriage. Stay out of the religious rites, and avoid the parts with alcohol, dancing between the sexes or immodesty. If the whole event is built on those, attend briefly or send a gift.
Attending for the sake of family ties and good relations is permissible. Taking part in the religious service is haram. If wine or other sin is at your own table, do not sit there; if it is elsewhere in the hall, you may stay, though leaving is better for someone people look up to. Congratulating someone on a marriage is not the same as congratulating on a religious festival and is allowed.
The four schools agree on this.
Explanation
Marriage is something every faith shares, and wishing a sibling or friend a happy marriage is part of good relations. The question is what happens around it.
- The ceremony: you may be present and seated. Do not join the prayers, hymns, kneeling or blessing. Standing when everyone stands for the bride is simple courtesy and fine.
- The reception: eat what is halal, drink soft drinks, and sit away from the bar if you can. Toasts with alcohol: raise water or simply smile.
- Dancing and music: leave the dance floor to others. Many Muslims slip out after the meal and speeches.
- Dress: wear something smart and modest. Women keep hijab and men avoid silk and gold.
If you are the bridesmaid or best man, explain early which parts you can do. Holding the rings, giving a speech about the couple and helping organise are fine. Leading a prayer or toast with wine is not. The four schools agree that joining the rites of another religion is not allowed.
Families usually value your presence more than your participation in every detail. Showing up with a kind gift and a warm word keeps the bond strong and reflects the good character Islam asks for. See non-Muslim family and entering a church.
The evidence
Quran, Surah Al-Mumtahana 60:8
لَّا يَنْهَىٰكُمُ ٱللَّهُ عَنِ ٱلَّذِينَ لَمْ يُقَٰتِلُوكُمْ فِى ٱلدِّينِ وَلَمْ يُخْرِجُوكُم مِّن دِيَٰرِكُمْ أَن تَبَرُّوهُمْ وَتُقْسِطُوٓا۟ إِلَيْهِمْ ۚ إِنَّ ٱللَّهَ يُحِبُّ ٱلْمُقْسِطِينَ ﴿٨﴾
Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly.
Kindness and good relations with peaceful non-Muslims are encouraged.
Quran, Surah Al-Furqaan 25:72
وَٱلَّذِينَ لَا يَشْهَدُونَ ٱلزُّورَ وَإِذَا مَرُّوا۟ بِٱللَّغْوِ مَرُّوا۟ كِرَامًۭا ﴿٧٢﴾
And [they are] those who do not testify to falsehood, and when they pass near ill speech, they pass by with dignity.
The believers do not attend falsehood as participants; the scholars apply this to joining rites of other faiths.
Where the ruling is recorded
- al-Hidaya, Kitab al-Karahiyya, the section on accepting an invitation where there is entertainment. A guest may stay at a gathering with some wrong away from the table, but should not sit at a table where it is done, and a person others follow should leave.
- Fatawa Mahmudiyya, the chapter on dealings with non-Muslims. Modern Hanafi fatwas on attending non-Muslim relatives' weddings while avoiding religious rites.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.