The 44-year-old will be inaugurated to replace Macky Sall, who ruled the West African country for 12 years.
The Senegalese Constitutional Council confirmed the victory of opposition candidate Basserou Diomaye Faye in the presidential elections.
Friday's confirmation paves the way for his inauguration as the country's fifth president, which is expected to take place on April 2.
The Supreme Court approved the preliminary results announced on Wednesday, based on a 100 percent vote count from polling stations.
Faye – the anti-establishment candidate and ally of popular opposition figure Ousman Sonko – won more than 54 percent of votes cast in last Sunday's postponed presidential election.
His closest competitor in the opinion polls, the ruling coalition candidate, Amadou Ba, chosen by outgoing President Macky Sall, received about 35 percent of the votes.
The council said that no objection was raised by the other contenders. At the age of 44, Faye became Africa's youngest president.
The African Union praised the “unanimous acceptance of the results.” Chairperson of the African Union Commission, Moussa Faki Mahamat, said he “warmly congratulates” Faye on his victory and wishes him “full success in his heavy and noble mission.”
French President Emmanuel Macron also extended his “warm congratulations” to Fay, his office said, and said France wanted to “continue and intensify the partnership” between the two countries.
Faye's victory came just 10 days after his release from prison. He said he wanted a “break” with the current political system.
Analysts said his victory reflects a protest against the outgoing leadership and divisions within the strong but weak ruling coalition.
“Osman is Diomai”
Millions of people in Senegal participated in voting last Sunday.
The elections came after three years of political turmoil that led to violent anti-government protests, which garnered greater support for the opposition.
Before the election, Faye was seen as a strong contender to replace Sall, after his ally Sonko was excluded from the ballot due to a suspended prison sentence following his conviction on defamation charges. He endorsed Sonko Faye to run in his place.
Although Faye was imprisoned last April and charged with contempt of court, defamation and acts likely to endanger public peace, after publishing a letter criticizing the judicial system, he was not convicted of any crime and was able to run for election.
Al Abdullah said: “The man who was imprisoned for more than 11 months, because of a Facebook post that the authorities considered a threat to the state’s sovereignty and security, is now at the head of one of the fastest growing economies in West Africa.” Nicolas Haque, Al Jazeera's correspondent from Dakar.
He added: “Faye is the youngest elected head of state in Africa and promises change for the Senegalese people.”
Faye, known as “Dumai”, ran under the slogan “Osman Moi Diumai”, which means “Osman is Diumai” in Wolof – strengthening the links between him and Sonko.
Both men studied law and worked as tax inspectors, where they met and spoke out against corruption, and later co-founded the now-defunct PASTEF party in 2014.
They described themselves as incorruptible tax inspectors who did not line their own pockets while others did.
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