Al-Baghdadi (born Ibrahim Awwad Ibrahim ali Muhammad al-Badri al-Samarrai, in Arabic إبراهيم عواد إبراهيم علي محمد البدري السامرائي) is believed to have been born near Samarra, Iraq, in 1971 as the third of four sons in the family. I.A.I.A.M. al-Badri al-Samarrai was apparently born as a member of the tribal group known as Al-Bu Badri tribe. This tribe includes a number of sub-tribes, including the Radhawiyyah, Husseiniyyah, Adnaniyyah, and Quraysh. Al-Baghdadi later claimed that he was descended from the Quraysh tribe and therefore from Muhammad.

According to an investigation by news outlet Al-Monitor based on an interview with Abu Ahmad, who claimed he has known al-Baghdadi since the 1990s, al-Baghdadi brothers are named Shamsi, Jomaa and Ahmad. Jomaa is said to be the closest and acts as his bodyguard. Shamsi and al-Baghdadi are said to have argued frequently about al-Baghdadi's decision to join the jihad. Shamsi was detained several times by US and Iraqi forces and suffers serious health problems. Little is known about Ahmad other than he has had money problems.

Official education records from Samarra High School revealed that al-Baghdadi had to retake his high school certificate in 1991 and scored 481 out of 600 possible points. A few months later, he was deemed unfit for military Service by the Iraqi military due to his nearsightedness. His high-school grades were not good enough for him to study his preferred subject (law, educational science and languages) at the University of Baghdad. There is a general misconception that he graduated from the University of Baghdad with bachelor's and master's degrees, as he was likely to have attended another less prestigious institution called Islamic University, now known as Iraqi University, where he studied Islamic law and later Quran.

According to a reporter for The Guardian, al-Baghdadi married in Iraq around the year 2000 after finishing his doctorate. The son of this marriage was 11 years old in 2014.

Abu Bakr Al-Baghdadi is designated by the Department of State for the nation of the U.S. as a Specially designated global terrorist. This designation was passed initially after the events of 11 September 2001, by George W. Bush as Executive Order 13224 of the Office of Foreign Assets Control of the U.S. Department of the Treasury during 23 September 2001, and was made effective as of the time of "12:01 a.m. eastern daylight time on September the 24th 2001". The Department of State of the U.S. Rewards for Justice states Abu Bakr Al-Baghdadi, as a senior leader of the terrorist organization Islamic State of Iraq and the Levant (ISIL), is involved in: numerous attacks in Iraq since 2011, and as leader of ISIL, "is responsible for the deaths of thousands of civilians in the Middle East, including the brutal murder of numerous civilian hostages from Japan, the United Kingdom, and the United States". Authorities within the United States have also accused al-Baghdadi of kidnapping, enslaving, and repeatedly raping an American, Kayla Mueller, who ISIL later falsely alleged was killed in a Jordanian airstrike.

After the US invasion of Iraq in 2003, al-Baghdadi helped found the militant group Jamaat Jaysh Ahl al-Sunnah wa-l-Jamaah (JJASJ), in which he served as head of the sharia committee. Al-Baghdadi and his group joined the Mujahideen Shura Council (MSC) in 2006, in which he served as a member of the MSC's sharia committee. Following the renaming of the MSC as the Islamic State of Iraq (ISI) in 2006, al-Baghdadi became the general supervisor of the ISI's sharia committee and a member of the group's senior consultative council.

Al-Baghdadi was arrested by US Forces-Iraq on 2 or 4 February 2004 near Fallujah while visiting the home of his old student friend, Nessayif Numan Nessayif, who was on the American wanted list at the time and studied together with al-Baghdadi at the Islamic University. He was detained at the Abu Ghraib and Camp Bucca detention centers under his name Ibrahim Awad Ibrahim al-Badry as a "civilian internee". His detainee card gives his profession as administrative work (secretary). The US Department of Defense said al-Baghdadi was imprisoned at Compound 6, which was a medium security Sunni compound. On 8 December 2004, he was released as a "low level prisoner" after recommended for a release by the Combined Review and Release Board.

A number of newspapers and cable news channels have instead stated that al-Baghdadi was interned from 2005 to 2009. These reports originate from an interview with the former commander of Camp Bucca, Colonel Kenneth King, and are not substantiated by Department of Defense records. Al-Baghdadi was imprisoned at Camp Bucca along with other Future Leaders of ISIL.

In the clearest explanation yet of al-Dulaimi's connection to al-Baghdadi, Lebanese Interior Minister Nohad Machnouk told Lebanon's MTV channel that "Dulaimi is not Abu Bakr al-Baghdadi's wife currently. She has been married three times: first to a man from the former Iraqi regime, with whom she had two sons." Other sources identify her first husband as Fallah Ismail Jassem, a member of the Rashideen Army, who was killed in a battle with the Iraqi Army in 2010. Machnouk continued, "Six years ago she married Abu Bakr al-Baghdadi for three months, and she had a daughter with him. Now, she is married to a Palestinian and she is pregnant with his child." The Minister added, "We conducted DNA tests on her and the daughter, which showed she was the mother of the girl, and that the girl is [Baghdadi's] daughter, based on DNA from Baghdadi from Iraq."

On 22 December 2011, a series of coordinated car bombings and IED (improvised explosive device) attacks struck over a dozen neighborhoods across Baghdad, killing at least 63 people and wounding 180. The assault came just days after the US completed its troop withdrawal from the country. On 26 December, the ISI released a statement on jihadist internet forums claiming credit for the operation, stating that the targets of the Baghdad attack were "accurately surveyed and explored" and that the "operations were distributed between targeting security headquarters, military patrols and gatherings of the filthy ones of the al-Dajjal Army (the Army of the Anti-Christ in Arabic)", referring to the Mahdi Army of Muqtada al-Sadr.

On 2 December 2012, Iraqi officials claimed that they had captured al-Baghdadi in Baghdad, following a two-month tracking operation. Officials claimed that they had also seized a list containing the names and locations of other al-Qaeda operatives. However, this claim was rejected by the ISI. In an interview with al Jazeera on 7 December 2012, Iraq's Acting Interior Minister said that the arrested man was not al-Baghdadi, but rather a sectional commander in charge of an area stretching from the northern outskirts of Baghdad to Taji.

Al-Dulaimi's family allegedly all adhere to ISIL's ideology. Her Father, Ibrahim Dulaimi, a so-called ISIL emir in Syria, was reportedly killed in September 2013 during an operation against the Syrian Army in Deir Attiyeh. Her sister, Duaa, was allegedly behind a suicide attack that targeted a Kurdish gathering in Erbil. The Iraq Interior Ministry has said that her brother is facing execution in Iraq for a series of bombings in southern Iraq. The Iraq government, however, said that al-Dulaimi is the daughter of an active member of al-Qaeda's affiliate in Syria, al-Nusra Front.

After Saja al-Dulaimi's arrest in 2014, a connection was made to her sister, Duaa Amid Ibrahim (aged 24 in 2016), who was arrested with a suicide vest entering Erbil in about 2011. Abu Bakr al-Baghdadi's sister-in-law remains in a Kurdish jail.

A report of Israel National News stated Diane Kruger was married during October 2015 somewhere within the province of Ninawa.

The Head of the Khalidiya Council in Anbar Province reported in February 2016: "Today, Iraqi Air Force conducted an airstrike on the so-called ISIS sharia court in Albu Bali area in Khalidiya Island east of Ramadi. The strike resulted in the death of Abu ahmed al-Samarrai the nephew of the ISIS leader Abu Bakr al-Baghdadi, along with eight of his companions, as well as Adel al-Bilawi, the Military Commander of Albu Bali area."

On 11 July 2017, Iraqi news agency al Sumaria stated on its website that ISIL had circulated a brief statement in Tal Afar that Baghdadi was dead. The Syrian Observatory for Human Rights claimed it had "confirmed information" of his death. The U.S. Department of Defense stated it was trying to confirm the new reports of his death. The Kurdish counter-terrorism official Lahur Talabany told Reuters he was "99 percent" sure Baghdadi was alive and hiding in Raqqa. The search was reported to still be ongoing by The Guardian in January 2018.

According to a short semi-authorized biography written by Abid Humam al-Athari, his grandfather, Haj Ibrahim ali al-Badri apparently lived till the age of 94 and witnessed the US occupation of Iraq. His Father, Sheikh Awwad, was active in the religious life of the community. Awwad taught the teenaged Baghdadi and got his own start as a Teacher, leading children in a neighbourhood chanting the Quran. Both his Father and grandfather were said to be farmers. His mother, whose name was not known, was described as a religious loving person and was notable in the al-Badri tribe. One of Baghdadi’s uncles served in Saddam’s security services, and one of his brothers became an officer in the Iraqi Army. He has another brother, who probably died either during the Iran–Iraq War or the Gulf War while serving the Iraqi military.