Sahih al-Bukhari (Arabic: صحيح البخاري, romanized: Ṣaḥīḥ al-Bukhārī) is a hadith collection and a book of sunnah compiled by the Persian scholar Muḥammad ibn Ismā‘īl al-Bukhārī (810–870) around 846. Alongside Sahih Muslim, it is one of the most valued books in Sunni Islam after the Quran. Both books are part of the Kutub al-Sittah, the six major Sunni collections of hadith of the Islamic prophet Muhammad. It consists of an estimated 7,563 hadith narrations across its 97 chapters. Sahih (صحيح) means "authentic" and Bukhari (بخاري) is the name of the author who was born in Bukhara in today's Uzbekistan.
 The original name of the work is Al-Jami Al-Musnad Al-Sahih Al-Mukhtasar Min Umur Rasul Allah Sallá Allah Alayhi Wa-Sallam Wa-Sunanihi Wa-Ayyamihi (الجامع المسند الصحيح المختصر من أُمور رسول الله صلى الله عليه وسلّم وسننه وأيامه), which means "The shortened authentic (sahih) collection with isnads from the affairs of the messenger, peace be upon him, and his traditions and his days".
 Sources differ on the exact number of hadiths in Sahih al-Bukhari, with definitions of hadith varying from a prophetic tradition or sunnah, or a narration of that tradition. Experts have estimated the number of full-isnad narrations in the Sahih at 7,563, with the number reducing to around 2,600 without considerations to repetitions or different versions of the same hadith. Bukhari chose these narrations from a collection of 600,000 narrations he had collected over 16 years. The narrations are distributed across 97 chapters covering fiqh (Islamic jurisprudence), among other subjects. Each chapter contains references to relevant verses from the Quran. It provides proper Islamic guidance in almost all aspects of Muslim life such as the method of performing prayers and other actions of worship directly from Muhammad.
 It is reported that Bukhari traveled widely throughout the Abbasid Caliphate from the age of 16. Bukhari found the earlier hadith collections including both ṣaḥīḥ (authentic, sound) and hasan narrations. He also found that many of them included daʻīf (weak) narrations. This aroused his interest in compiling hadith whose authenticity was beyond doubt. 
 What further strengthened his resolve was something his teacher and contemporary hadith scholar Ishaq Ibn Rahwayh had told him. Bukhari narrates, "We were with Ishaq Ibn Rahwayh who said, "If only you would compile a book of only authentic narrations of the Prophet." This suggestion remained in my heart so I began compiling the Sahih." Bukhari also said, "I saw the Prophet in a dream and it was as if I was standing in front of him. In my hand was a fan with which I was protecting him. I asked some dream interpreters, who said to me, 'You will protect him from lies'. This is what compelled me to produce the Sahih."
 Bukhari imposed four conditions the narrators of a hadith must meet, in order for the narration to be included in his Sahih:
 Bukhari began organizing his book in the Masjid al-Haram in Mecca, before moving to the Al-Masjid an-Nabawi in Medina. Bukhari completed writing the book in Bukhara around 846 (232 AH), before showing it to his teachers for examination and verification. Ibn Hajar al-Asqalani quoted Abu Jaʿfar al-'Uqaili as saying, "After Bukhari had written the Sahih, he showed it to Ali ibn al-Madini, Ahmad ibn Hanbal, Yahya ibn Ma'in as well as others. They examined it and testified to its authenticity with the exception of four hadith." Ibn Hajar then concluded with al-'Uqaili's saying, "And those four are as Bukhari said, they are authentic." Bukhari spent the last twenty-four years of his life visiting other cities and scholars, making minor revisions to his book and teaching the hadith he had collected. In every city that Bukhari visited, thousands of people would gather to listen to him recite traditions.
 Each version of the Sahih is named by its narrator. Ibn Hajar al-Asqalani in his book Nukat asserts the number of narrations is the same in each version. There are many books that noted differences between the different versions, the best known being Fath al-Bari. The version transmitted by Muhammad ibn Yusuf al-Firabri (died 932), a trusted student of Bukhari, is the most famous version of the Sahih al-Bukhari today. All modern printed version are derived from this version. Al-Khatib al-Baghdadi quoted al-Firabri in History of Baghdad: "About seventy thousand people heard Sahih Bukhari with me." al-Firabri is not the only transmitter of Sahih al-Bukhari. Many others narrated the book, including Ibrahim ibn Ma'qal (died 907), Hammad ibn Shakir (died 923), Mansur Burduzi (died 931) and Husain Mahamili (died 941).
 The Orientalist Manjana said in Cambridge in 1936 that the oldest manuscript he had come across up to that point was written in 984 CE/370 AH, according to the narration of al-Mirwazi from al-Farbari The oldest full manuscript which was printed by ISAM is from 1155/550 AH. As is the norm in hadith studies Bukhari would have recited his Sahih to a large number of his students who would not only listen to it, but memorise it word for word from him and copy it in its entirety. Students would then check their own copies against Bukhari’s personal copy and would only receive permission to transmit and teach once Bukhari himself was happy with their ability to do so. This way, the isnad (chain of narration) would be traceable and also have multiple routes back to the teacher.
 The orientalist Manjana said in Cambridge in 1936 that the oldest manuscript he had come across up to that point was written in 984 (370 AH), according to the narration of al-Mirwazi from al-Firabri. The oldest full manuscript is a version on the narration of Abu Dharr al-Heravi (died 1043) written in Maghrebi script, present in the Süleymaniye Library in Istanbul is from 1155 (550 AH).
 The number of detailed commentaries on the Sahih are numbered around 400, including Fayd al-Bari ala Sahih al-Bukhari and Anwar al-Bari sharh Sahih al-Bukhari by Anwar Shah Kashmiri, Lami al-Darari ala Jami al-Bukhari by Rashid Ahmad Gangohi, Tafsir al-Gharib ma fi al-Sahihayn by al-Humaydī (died 1095), Ibn Kathir's (died 1373) Sharh, Fath al-Bari by Ibn Hajar al-'Asqalani (died 852 AH), Al-Tawshih by al-Suyuti (died 1505), Irshad al-Sari by al-Qastallani (died 1517), Umdat al-Qari by Badr al-Din al-Ayni, and Al-Tanqih by al-Zarkashi (died 1392), Kashf al-Bari Amma fi Sahih al-Bukhari by Saleemullah Khan. Modern commentaries are also written by Saeed Ahmad Palanpuri, Kausar Yazdani, Muhammad Taqi Usmani, and Muhammad Zakariyya Kandhalawi.
 Few scholars have commented on Bukhari's reasons behind naming the chapters in his Sahih, known as tarjumat al-bab. Ibn Hajar al-Asqalani is noted to be one of them. Shah Waliullah Dehlawi had mentioned 14 reasons, later modified by Mahmud al-Hasan to make it 15. Kandhlawi is noted to have found as many as 70, even writing a book on the topic, Al-Abwab wa al-Tarajim li Sahih al-Bukhari.
 Sahih al-Bukhari was originally translated into English by Muhammad Taqi-ud-Din al-Hilali and Muhammad Muhsin Khan, titled The Translation of the Meanings of Sahih al-Bukhari: Arabic-English (1971), derived from the Arabic text of Fath Al-Bari, published by the Egyptian Maktabat wa-Maṭba'at Muṣṭafá al-Bābī al-Ḥalabī in 1959. It is published by Al Saadawi Publications and Darussalam Publications and is included in the USC-MSA Compendium of Muslim Texts. Large numbers of hadith narrations included in Hilali and Khan's work have been translated by Muhammad Ali and Thomas Cleary. The book is also available in numerous languages, including Urdu, Bengali, Bosnian, Tamil, Malayalam, Albanian, Malay, and Hindi, among others.
 In 2019, the Arabic Virtual Translation Center in New York translated and published the first complete English translation of Sahih al-Bukhari titled Encyclopedia of Sahih Al-Bukhari, including explanatory notes, a glossary of every term, and biographies of all narrators in the isnad.
 Sunni Muslims regard Sahih al-Bukhari as one of the two most important books among the Kutub al-Sittah alongside the Sahih Muslim, written by al-Bukhari's student Muslim ibn al-Hajjaj. The two books are known as the Sahihayn (The Two Sahihs). Al-Nawawi wrote about Sahih al-Bukhari, "The scholars, may God have mercy on them, have agreed that the most authentic book after the dear Quran are the two Sahihs of Bukhari and Muslim." Siddiq Hasan Khan (died 1890) wrote, "All of the Salaf and Khalaf assert that the most authentic book after the book of Allah is Sahih al-Bukhari and then Sahih Muslim."
 In the Introduction to the Science of Hadith, Ibn al-Salah wrote: "The first to author a Sahih was Bukhari [...], followed by Abū al-Ḥusayn Muslim ibn al-Ḥajjāj an-Naysābūrī al-Qushayrī, who was his student, sharing many of the same teachers. These two books are the most authentic books after the Quran. As for the statement of al-Shafi'i, who said, "I do not know of a book containing knowledge more correct than Malik's book [Muwatta Imam Malik]", [...] he said this before the books of Bukhari and Muslim. "The book of Bukhari is the more authentic of the two and more useful." Ibn al-Salah also quoted Bukhari as having said, "I have not included in the book [Sahih al-Bukhari] other than what is authentic and I did not include other authentic hadith for the sake of brevity." In addition, al-Dhahabi quoted Bukhari as having said, "I have memorized one hundred thousand authentic hadith and two hundred thousand which are less than authentic."
 Criticism has also been directed at apparent contradictions within Bukhari regarding the ahruf of the Quran. Some narrations state the Quran was revealed only in the dialect of Muhammad's tribe, the Quraysh, while others state it was revealed in seven ahruf. Certain prophetic medicine and remedies espoused in Bukhari, such as cupping, have been noted for being unscientific. Sunni scholar Ibn Hajar al-Asqalani, on the basis of contrary archaeological evidence, criticised the hadith which claimed that Adam's height was 60 cubits and human height has been decreasing ever since.
 Other hadiths contradict historical facts: e.g. hadith number 1221 implies Abu Sufyan ibn Harb died in Shām when he actually died in Medina; hadith number 3800 claims all the Sahaba who witnessed the Battle of Badr died before the end of the murder of Uthman; hadith number 5,560 says Muhammad died at 60 years old, instead of the actual 63 years old; there are also serious contradictions between hadiths regarding the timing of Qadr Night.
 In the 2003 book The Idea of Women in Fundamentalist Islam, Lamia Shehadeh used gender theory to critique an ahaad hadith about women's leadership. Another hadith reported by Abu Hurairah was criticized by Fatema Mernissi for being reported out of context and without any further clarification in the Sahih. The clarification is given in a hadith reported by Aisha in al-Zarkashi's (1344–1392) hadith collection. According to Charles Kurzman, this case raises the question of whether other narrations in Bukhari have been reported incompletely or lack proper context. In 2017, Rachid Aylal, a Quranist, published a book criticizing the Sahih, titled Sahih Al-Bukhari: The End of a Legend. It was banned in Morocco for disturbing spiritual security, due to pressure from Islamists.
 On August 29, 2022, Ministry of Justice of the Russian Federation has included Sahih al-Bukhari into the federal list of extremist materials (except containing surahs, ayahs and quotes from the Quran) after the Supreme Court of Tatarstan supported the Laishevo District Court's decision to recognize the Sahih as extremist with its appellate ruling of July 5, 2022.