Saad Hariri was born in Riyadh, Saudi Arabia on 18 April 1970, and is the son of Rafic Hariri and his first wife Nidal Bustani, an Iraqi. In addition to his native Arabic, Hariri speaks English, French and Italian. He graduated in 1992 from the McDonough School of Business at Georgetown University with a degree in business administration.

Saad Hariri born in 1970 in Riyadh is the second son of Lebanese Prime Minister Rafic Hariri and his first wife Nidal Bustani, an Iraqi. He has an older brother Bahaa Hariri (born 1967) and another brother Houssam Hariri who died young in a traffic accident. After his parents divorced, his father married Nazik Hariri (née Audi) in 1976. Saad Hariri has two half-brothers and one half-sister from his father’s second marriage: Ayman Hariri, (born 1978), Fahd Hariri, (born c. 1980/81) and Hind Hariri, a sister (born 1984).

Hariri holds multiple citizenships: Lebanese, Saudi Arabian and French. He married Lara Al Azem in 1998, the daughter of Bashir Al Azem, an influential and wealthy Syrian construction magnate. They have three children: Houssam (born 1999), Loulwa (born 2001), and Abdulaziz (born 2005).

On 20 April 2005, the Hariri family announced that Saad Hariri would lead the Future Movement, an essentially Sunni movement that was created and led by his late father. He was the leader of the March 14 Alliance, a coalition of political groups born out of the Cedar Revolution which, through mass popular demonstrations and Western support, led to the withdrawal of Syrian troops from Lebanon in 2005 after a 29-year presence.

In 2007, French president Jacques Chirac awarded Saad Hariri the Légion d’honneur, a French order of merit.

On 12 January 2011, minutes after Hariri posed for pictures with President Barack Obama in the Oval Office, the opposition parties resigned from his unity government cabinet, causing its collapse. The withdrawal of Hezbollah and its allies was due to political tensions arising from investigations into the assassination of Rafic Hariri. Hezbollah operatives had been accused of assassinating Rafic Hariri.

Hariri continued on for four months as caretaker Prime Minister. The new Lebanese government was formed on 13 June 2011 and headed by Najib Mikati. Mikati created an 8 March-led government coalition.

In 2011, he was said to have a net worth of $2 billion. As of May 2018, his net worth is estimated to be $1.36 billion.

On 12 December 2012, Syria issued a warrant for the arrest of Hariri, Future bloc deputy Okab Sakr and Free Syrian Army official Louay Almokdad on charges of arming and providing financial support for Syrian opposition groups. Hariri released a statement in response, describing Bashar Assad as a “monster”.

In 2013, Hariri allegedly paid his South African energy drink saleswoman and escort, Candice van der Merwe, a $16 million cash gift after meeting her in the Seychelles. In 2019, South African courts sued van der Merwe for failing to pay income taxes on the amount, despite her claims that it was a gift.

Hariri lived in Paris from 2011 to 2014 for safety reasons, and returned to Lebanon on 8 August 2014.

Following more than two years of deadlock in electing a president, Michel Aoun was elected. Shortly after, Aoun signed a decree appointing Hariri as prime minister for the second time and he took office on 18 December 2016.

On 4 November 2017, in a televised statement from Saudi Arabia, Hariri tendered his resignation from office, citing Iran’s and Hezbollah’s political over-extension in the Middle East region and fears of assassination. Iran vehemently rejected Saad Hariri’s remarks and called his resignation part of a plot by the United States, Israel, and Saudi Arabia to heighten Middle Eastern tensions. The Lebanese Army responded with a statement that intelligence in its possession in addition to ongoing arrests and investigations had not revealed “the presence of any plan for assassinations in the country.”

In mid-October 2019, a popular protest movement began calling for increased accountability and transparency in politics. His government was widely viewed as corrupt by the Lebanese people. On 29 October, Hariri offered his resignation as a concession, saying “This is in response to the will and demand of the thousands of Lebanese demanding change”. The following day, President Michel Aoun accepted the resignation but requested that Hairi remain in office till a successor was appointed. Hassan Diab, the former education minister, was appointed to the role on 21 January 2020. On 10 August 2020, Diab resigned in the aftermath of the Beirut explosion due to mounting political pressure and anger at the Lebanese government for their failure to prevent the disaster, exacerbated by existing political tensions and upheavals within the country.