Short answer
Yes. Believing that black cats, the number 13, Friday the 13th, broken mirrors or a certain month bring bad luck is haram in Islam. The Prophet ﷺ called taking bad omens (tiyarah) a form of shirk. Good and harm come only from Allah. Optimism, hoping for good from a kind word, is encouraged.
Belief in bad omens is haram, and believing that the thing itself causes harm is shirk. If a superstitious thought crosses your mind, ignore it, rely on Allah and carry on with what you planned.
The four schools agree on this.
Explanation
The Arabs before Islam would release a bird before a journey: if it flew right, they went; if it flew left, they stayed home. The Prophet ﷺ abolished this. He said there is no tiyarah (bad omen), no owl omen, and no bad luck in the month of Safar. He repeated three times that tiyarah is shirk. Ibn Mas'ud added that such thoughts cross everyone's mind, but Allah removes them through trust in Him.
Modern superstitions work the same way:
- Black cats: cats are pure animals the Prophet ﷺ spoke well of. Their colour brings neither luck nor harm.
- The number 13 and Friday the 13th: no number is unlucky, and Friday is the best day of the week.
- Safar or certain wedding dates: the hadith itself names Safar to cancel this belief.
- Broken mirrors, walking under ladders, itchy palms, sneezing omens: all baseless.
- 'Knock on wood': say mashaAllah or InshaAllah instead.
Islam does allow fa'l, optimism. The Prophet ﷺ liked hearing a good word, such as someone being called by a name meaning 'success', and taking hope from it. That is hope in Allah, not a belief that a thing controls your fate.
The Quran tells of Pharaoh's people, who blamed every misfortune on Musa and called him a bad omen. Allah answered that their fortune is with Him. The four schools agree on this ruling. See also Tawheed, shirk and kufr.
The evidence
Quran, Surah Al-A'raaf 7:131
فَإِذَا جَآءَتْهُمُ ٱلْحَسَنَةُ قَالُوا۟ لَنَا هَٰذِهِۦ ۖ وَإِن تُصِبْهُمْ سَيِّئَةٌۭ يَطَّيَّرُوا۟ بِمُوسَىٰ وَمَن مَّعَهُۥٓ ۗ أَلَآ إِنَّمَا طَٰٓئِرُهُمْ عِندَ ٱللَّهِ وَلَٰكِنَّ أَكْثَرَهُمْ لَا يَعْلَمُونَ ﴿١٣١﴾
But when good came to them, they said, "This is ours [by right]." And if a bad [condition] struck them, they saw an evil omen in Moses and those with him. Unquestionably, their fortune is with Allah, but most of them do not know.
Blaming misfortune on omens is condemned; fortune is with Allah.
Sahih al-Bukhari 5757
Sahih... لا عدوى ولا طيرة ولا هامة ولا صفر ...
"There is no contagion by itself, no bad omen, no owl omen and no bad luck in Safar."
Superstitions about omens, birds and months are cancelled.
Sunan Abi Dawud 3910
Graded sahih... الطيرة شرك الطيرة شرك ...
"Taking bad omens is shirk. Taking bad omens is shirk."
Believing in bad luck from things is a form of shirk.
Sahih al-Bukhari 5756
Sahih... لا عدوى ولا طيرة ويعجبني الفأل ...
"There is no contagion by itself and no bad omen, and I like optimism."
Hope and optimism are allowed, omens are not.
Where the ruling is recorded
- Fath al-Bari (Ibn Hajar), Kitab al-Tibb, chapters on tiyarah and fa'l. Explains the difference between forbidden omens and permitted optimism.
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.