The swearing-in ceremony took place at Kuala Lumpur's National Palace.
Ibrahim, 75, was appointed prime minister by King Sultan Abdullah Ri'ayatuddin Al-Mustafa Billah Shah five days after the 15th general elections, which panned out with a hung parliament, leaving it up to the monarch to choose the party with the most constituencies.
Though Ibrahim-led Alliance of Hope, or Pakatan Harapan (PH), has secured most seats in parliament in the Nov. 19 general elections, it is still short of forming a government on its own.
The PH secured 82 seats, while former Prime Minister Muhyiddin Yassin-led National Alliance or Perikatan Nasional (PN) got 73 seats.
It is, nonetheless, unclear which party or alliance Ibrahim will choose to form the government, which has to face a slew of challenges lying ahead, ranging from economy to political stability.
Earlier in the day, Malaysia’s Council of Rulers decided to back Ibrahim, a former deputy prime minister, as the country’s new premier, the Malaysiakini news website reported.
On Tuesday, the king met with the two leaders and proposed a unity government, which Yassin rejected. Later that day, the monarch summoned eight other council members for a meeting to end the deadlock.
Support from the National Front, or Barisan Nasional (BN), with 30 lawmakers, is seen to be a decisive factor in the new setup.
Another bloc Sarawak Parties Alliance, or Gabungan Parti Sarawak (GPS), with 23 seats, had indicated it would support the Yassin-led group but was indecisive.
To be the leader of the parliament, any party or alliance must secure the support of at least 112 lawmakers in a 222-seat house.
Ibrahim’s rise to power marks a stunning comeback for a man who at the peak of his political career was suddenly sacked and jailed by the government of former Prime Minister Mahathir Mohammad in the 1990s.
Once seen as a highly-potential replacement for Mahathir, he fell out with the former “iron man” over the handling of the Southeast Asian country’s economy during the famous Asian financial crisis.
Subsequently, he was convicted and jailed on corruption and sodomy charges, which were widely believed to be politically motivated.
His conviction was overturned in 2004, but he was sentenced to prison again in 2015 on a similar fresh charge.
He was pardoned by the king after Mahathir reconciled with him on the heels of a massive corruption scandal involving then-Prime Minister Najib Razak in 2018.
Mahathir and Ibrahim, later, joined hands and defeated Razak’s party in the 2018 elections, bringing the former to the Prime Minister's Office again.
However, the top job slipped from his hand again when a deal in which then-95-year-old Mahathir would hand over power to Ibrahim fell through in 2020.
Source: Anadolu Agency