The 44-year-old had never before held an elected office. However, several African leaders attended the ceremony in the new town of Diamniadio, near the capital Daka
Mr Faye was released from prison less than two weeks before the March 24 election, along with popular opposition figure Ousmane Sonko, following a political amnesty announced by outgoing president Macky Sall.
It is the former tax inspector’s first time in elected office.
Aissata Sagna, a factory worker who helped with Mr Faye’s campaign, said: “It’s the culmination of a long struggle for democracy and the rule of law.
“This is a day of celebration for us, even if we have lost young people killed during the demonstrations.”
The election followed months of unrest ignited by the arrests last year of Mr Sonko and Mr Faye and concerns that the president would seek a third term despite the constitution requiring him to step down.
Human rights groups said that dozens of people had been killed in the protests and about 1,000 jailed.
Mr Faye was arrested for alleged defamation last year, while Mr Sonko faced a number of charges, including a prolonged legal battle that started when he was accused of rape in 2021.
He was acquitted of the rape charges but was convicted of corrupting youth and sentenced to two years in prison last summer.
Mr Sonko’s supporters say his legal troubles were part of a government effort to derail his candidacy.
While Mr Sall eventually ruled out seeking a third term, he then abruptly postponed the election in February with only weeks to go, triggering another wave of protests.
The decision was overturned by the Constitutional Court and the election was held last month.
Mr Faye’s victory is seen as reflecting the will of young people frustrated with widespread unemployment and former colonial ruler France, which critics say is using its relationship with Senegal to enrich itself.
In his first speech as president-elect, he promised to fight corruption and reform the economy.
