Born and raised in Makeni in northern Sierra Leone, Koroma spent more than 24 years working in the private insurance industry before entering politics in 2002.

In the 2007 presidential election run-off, Koroma received 54.6% of the vote and defeated incumbent Vice-President Solomon Berewa of the ruling SLPP.

[13] Ernest Bai Koroma was born on 2 October 1953 in Makeni,[14] Bombali District in the Northern Province of British Sierra Leone.

He served as former Attorney General of Sierra Leone, and also held several other government ministry positions under presidents Joseph Saidu Momoh and Ahmad Tejan Kabbah.

[22] In 2002 it was announced that the All People's Congress (APC) would hold their convention to elect a new leader that would challenge president Ahmad Tejan Kabbah of the SLPP who faced re-election for a second five-year term.

Koroma has been charged with four offences including treason for his alleged role in failed military attempt coup to topple the West African country's government in November.

Koroma was allegedly the target of an assassination attempt in the early hours of 23 July 2007 in Bo, Sierra Leone's second largest city (a traditional stronghold of the SLPP), when, according to the APC, a group of armed men led by Tom Nyuma, who was a participant in the 1992 coup that ousted the APC from power, attempted to enter Koroma's hotel room to kill him.

[33] In the first round of the 2007 presidential election in Sierra Leone, held on 11 August, Koroma garnered 44.3% of the votes, ahead of Solomon Berewa of the ruling SLPP, who received 38.3%.

[35] In an interview with Reuters on 13 September, Koroma said that he wanted to run the country "like a business concern", with a focus on agriculture and tourism rather than mining, and fight firmly against corruption.

[36] On 17 September, the Sierra Leone National Electoral Commission declared Koroma to be the winner of the election with 54.6% of the vote,[37] although the SLPP disputed the results.

[40] On 21 September, Koroma left Sierra Leone for a diplomatic visit to neighboring Guinea and Liberia, his first trip outside the country as President.

[44] According to Koroma, he was willing to take additional time to find the right people;[42] others, however, speculated that the delay was due to maneuvering within the APC for Cabinet positions.

[45][46] Koroma promised zero tolerance on corruption, to fight against the mismanagement of the country's resources and that he "would run Sierra Leone like a business concern", emphasising agriculture and tourism.

In April 2010, Koroma signed into law the country's free health care program for pregnant women, nursing mothers and children under the age of five.

[52][53] The Koroma presidency, with the financial help of the United Nations, has implemented a free healthcare program for children, pregnant women and breastfeeding mothers.

[54][55] However, many experts and critics say most of the money meant to fund the program has been mismanaged and misused by senior government officials due to corruption.

[56][57] President Koroma named experts to investigate the allegation, and some senior government officials linked to the Ebola funds were fired and suspended.

President Koroma has often made unannounced visit to several poor Sierra Leonean neighborhood, and he is often seen waving to the people in his presidential motorcade.

President Koroma was criticized after several people were shot dead by Sierra Leone Police officers in the Eastern city of Koidu Town in 2007 and again in 2012 at protests rallies against poor living conditions and against the mining companies in Kono District.

[71] The UK continues to be the largest donor to Sierra Leone, giving more money per person than to any other nation, and promising to raise aid by a further 50 million pounds sterling in 2010.

[72] In a 2009 BBC report by Humphrey Hawksley, some British diplomats and aid workers raised concerns about the slow pace of development in the country stressing on the problem of corruption, and asking whether almost a decade after the war – British military and post-war aid assistance has gone in vain as the country still struggle with poverty and massive unemployment.

[73] President Koroma also worked closely with British Prime Minister Gordon Brown, who increased the United Kingdom's aid to and cooperation with Sierra Leone even further.

[75] Koroma pushed through arrest and prosecution authority for the Sierra Leone Anti-corruption Commission, and naming former Human Rights lawyer Abdul Tejan-Cole its head immediately after his election.

[83] At the African Union summit held at the Egyptian resort of Sharm El Sheikh in 2008, he was quoted saying, "The people of Zimbabwe have been denied their democratic rights.

[87][88][89] Koroma was re-elected as President in the 17 November 2012 presidential election with 58.7% of the vote, defeating his main opponent, Retired Brigadier Julius Maada Bio of the SLPP, who received 37.4%.

[6][7][8][9] Koroma was sworn in as President for his second and final term by Chief Justice Umu Hawa Tejan Jalloh at the State House in Freetown on 23 November, the same day he was declared the winner of the election.

In 2017 it was announced that the All People's Congress (APC) would hold their convention to choose a new leader that will challenge Julius Maada Bio of the SLPP for the presidency during the 2018 elections.

Koroma, on his own, chose Samura Kamara instead of going through the due process of elections- a move that was unpopular and angered the majority of APC supporters.