Short answer
Yes, a Muslim may attend the funeral of a non-Muslim relative, neighbour or colleague to show respect and support the family. Do not take part in religious rites such as prayers, hymns or kneeling, and do not ask Allah to forgive them. You may offer kind words of condolence.
Attending a non-Muslim's funeral is permissible, especially for a relative, as long as one does not join in the rites of another religion. If a Muslim's non-Muslim parent dies and no co-religionist relative takes care of the body, the Muslim may wash it simply, wrap it in a cloth and bury it, without the sunnah rites.
The four schools agree on this.
Explanation
Many Muslims, especially converts, have non-Muslim parents, siblings and friends. Islam does not ask you to cut off from them at their death. Kindness to non-Muslims who live in peace with you is praised in the Quran, and being there for a grieving family is part of good character.
What is fine:
- Attending the funeral, the viewing or the burial to support the family.
- Standing respectfully. The Prophet ﷺ once stood for the funeral of a Jewish man and said, "Was it not a soul?"
- Saying kind words to the family and helping them practically with food, travel or arrangements.
- A Muslim child helping to bury a non-Muslim parent when no one else will. The Prophet ﷺ told Ali to go and bury his father Abu Talib.
What to avoid:
- Joining in prayers, hymns, crossing yourself, kneeling or other acts of worship of another religion.
- Asking Allah to forgive a person who died upon disbelief; the Quran forbids this, even for relatives.
- Eating food or drink that is not halal at the reception.
You can sit quietly during a church service without taking part. If the service is mainly worship, you may stand outside and join for the burial or the gathering after.
Inheritance. A Muslim does not inherit from a non-Muslim relative under Islamic law, and the four schools agree. Money they left you by will or gave you while alive is a separate matter; see who inherits in Islam. For words of comfort, see condolence in Islam.
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 to peaceful non-Muslims, including at a funeral, is allowed and praised.
Quran, Surah At-Tawba 9:113
مَا كَانَ لِلنَّبِىِّ وَٱلَّذِينَ ءَامَنُوٓا۟ أَن يَسْتَغْفِرُوا۟ لِلْمُشْرِكِينَ وَلَوْ كَانُوٓا۟ أُو۟لِى قُرْبَىٰ مِنۢ بَعْدِ مَا تَبَيَّنَ لَهُمْ أَنَّهُمْ أَصْحَٰبُ ٱلْجَحِيمِ ﴿١١٣﴾
It is not for the Prophet and those who have believed to ask forgiveness for the polytheists, even if they were relatives, after it has become clear to them that they are companions of Hellfire.
Asking forgiveness for someone who died upon shirk is not allowed.
Sahih al-Bukhari 1312
Sahih... مرت به جنازة فقام فقيل له إنها جنازة يهودي فقال أليست نفسا ...
"A funeral passed by him and he stood. He was told it was the funeral of a Jew, and he said: was it not a soul?"
The Prophet ﷺ stood out of respect for a Jewish man's funeral.
Sunan Abi Dawud 3214
Graded sahih... اذهب فوار أباك ...
"Go and bury your father."
A Muslim son was told to see to his non-Muslim father's burial.
Sahih al-Bukhari 6764
Sahih... لا يرث المسلم الكافر ولا الكافر المسلم ...
"A Muslim does not inherit from a disbeliever, nor a disbeliever from a Muslim."
Difference of religion bars inheritance both ways.
Where the ruling is recorded
- al-Hidaya, Kitab al-Salah, Bab al-Jana'iz. A Muslim relative washing, shrouding and burying a non-Muslim in a simple manner.
- al-Fatawa al-Hindiyya, Kitab al-Karahiyah. Visiting and condoling non-Muslims.
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.