Weah succeeds Ellen Johnson Sirleaf in the country's first peaceful democratic transfer of power in seven decades.
Former international football star George Weah has been sworn in as president of Liberia, the first peaceful democratic transfer of power in the West African country in more than seven decades.
Weah won 61.5 percent of the votes in December's election run-off, beating outgoing vice president Joseph Boakai who garnered 38.5 percent of the ballot.
Voter turnout was 55.8 percent, or just over 1.2 million people, according to the election commission.
The former world footballer of the year succeeded Ellen Johnson Sirleaf, Africa's first elected female president.
Weah entered politics after retiring from football in 2002 and run for the presidency in 2005 losing to Sirleaf.
The last peaceful transfer of power between two democratically elected presidents took place in Liberia in 1944, when president Edwin Barclay was replaced by William Tubman.
The swearing in ceremony at a stadium near the Liberian capital, Monrovia was attended by more than dozen African and foreign dignitaries, including heads of state from Ghana, Nigeria, South Africa, Mali, Ivory Coast and Guinea.
Many Liberians regard the 51-year-old as a hero for his incredible rags-to-riches tale. He was born in a slum in Monrovia, but found fame in international football.