Short answer
No one. Allah is the Creator, not a creation. He has always existed with no beginning and will exist with no end. The Prophet ﷺ said Shaytan would put this question in people's minds, and taught that when it comes you should seek refuge in Allah and stop.
Sunni creed holds that Allah is pre-eternal (qadim) and everlasting (baqi): His existence has no beginning and depends on nothing. Everything other than Allah came into being and needs a cause; Allah does not. A passing thought of this kind is not a sin; the cure is to seek refuge in Allah and turn away from it.
The four schools agree on this.
Explanation
The question assumes Allah is like the things around us, which all had a beginning and so needed a maker. Islam teaches the opposite. Nothing is like Allah (42:11). He is the First, with nothing before Him, and the Last, with nothing after Him (57:3). He neither begets nor is born (112:3).
Scholars of kalam (theology) explain it this way. A chain of causes cannot go back forever with no first cause, or nothing would exist at all. So there must be a being who exists without needing a cause, and that being is Allah. Asking who made Him is like asking what came before the very first thing. A hadith in al-Bukhari puts it simply: Allah was, and there was nothing other than Him.
The Prophet ﷺ expected this whisper. He said Shaytan comes to a person and asks, "Who created this? Who created that?" until he asks, "Who created your Lord?" When it reaches that point, the person should seek refuge in Allah and stop. So the answer is not endless arguing but a clear stop.
If this thought troubles you, you are not alone, and it does not make you a disbeliever. Some Companions felt thoughts so bad they could not speak them, and the Prophet ﷺ called their hatred of those thoughts clear faith. Say a'udhu billahi min ash-shaytan ir-rajim (I seek refuge in Allah from the accursed Shaytan), say amantu billah (I believe in Allah), and busy yourself with something else. If the thoughts keep coming, talk to a scholar you trust.
The evidence
Quran, Surah Al-Hadid 57:3
هُوَ ٱلْأَوَّلُ وَٱلْءَاخِرُ وَٱلظَّٰهِرُ وَٱلْبَاطِنُ ۖ وَهُوَ بِكُلِّ شَىْءٍ عَلِيمٌ ﴿٣﴾
He is the First and the Last, the Ascendant and the Intimate, and He is, of all things, Knowing.
Allah has no beginning and no end, so He was not brought into being.
Quran, Surah Al-Ikhlaas 112:3
لَمْ يَلِدْ وَلَمْ يُولَدْ ﴿٣﴾
He neither begets nor is born,
Allah was not born from anything and has no origin.
Quran, Surah Ash-Shura 42:11
فَاطِرُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۚ جَعَلَ لَكُم مِّنْ أَنفُسِكُمْ أَزْوَٰجًۭا وَمِنَ ٱلْأَنْعَٰمِ أَزْوَٰجًۭا ۖ يَذْرَؤُكُمْ فِيهِ ۚ لَيْسَ كَمِثْلِهِۦ شَىْءٌۭ ۖ وَهُوَ ٱلسَّمِيعُ ٱلْبَصِيرُ ﴿١١﴾
[He is] Creator of the heavens and the earth. He has made for you from yourselves, mates, and among the cattle, mates; He multiplies you thereby. There is nothing like unto Him, and He is the Hearing, the Seeing.
Allah is not like created things, which need a maker.
Sahih al-Bukhari 3276
Sahih... مَنْ خَلَقَ رَبَّكَ فَإِذَا بَلَغَهُ فَلْيَسْتَعِذْ بِاللَّهِ وَلْيَنْتَهِ ...
"Shaytan asks, "Who created your Lord?" When he reaches that, let the person seek refuge in Allah and stop."
Shows the question comes from Shaytan and that the cure is to seek refuge and stop.
Sahih al-Bukhari 3191
Sahih... كَانَ اللَّهُ وَلَمْ يَكُنْ شَىْءٌ غَيْرُهُ ...
"Allah existed, and there was nothing other than Him."
Shows that Allah existed before everything, with nothing before Him.
Sahih Muslim 132
Sahih... ذَاكَ صَرِيحُ الإِيمَانِ ...
"That is clear faith."
Said of Companions who hated the evil thoughts that came to them, showing such thoughts do not cancel faith.
Where the ruling is recorded
- al-Aqida al-Tahawiyya, Section on Allah being pre-eternal without beginning. States that Allah is eternal without beginning and everlasting without end.
- Sharh al-Aqa'id al-Nasafiyya (al-Taftazani), Section on the world being originated. Argues that the world came into being and needs a Maker who is not originated.
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.