A left-wing pan-Africanist, Bassirou Diomaye Faye, has been sworn in on Tuesday as Senegal's youngest president.
Faye swept the poll at a first-round victory on a pledge of radical reform just 10 days after he was released from prison.
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 Dakar.
"Before God and the Senegalese nation, I swear to faithfully fulfil the office of President of the Republic of Senegal," Faye swore before the gathered officials.
He also vowed to "scrupulously observe the provisions of the Constitution and the laws" and to defend "the integrity of the territory and national independence, and to spare no effort to achieve African unity."
The formal handover of power with outgoing President Macky Sall will take place at the presidential palace in Dakar.
Faye was among a group of political opponents freed from prison 10 days before the March 24 presidential ballot under an amnesty announced by Sall, who had tried to delay the vote.
Faye's campaign was launched while he was still in detention.
The former tax inspector becomes the West African state's fifth president since independence from France in 1960.
Working with his populist mentor, Ousmane Sonko, who was barred from the election, Faye declared their priorities in his victory speech: national reconciliation, easing a cost-of-living crisis and fighting corruption.
The anti-establishment leader has vowed to restore national sovereignty over key assets such as the oil, gas and fishing sectors.
Faye wants to leave the regional CFA franc, which he sees as a French colonial legacy, and to invest more in agriculture with the aim of reaching food self-sufficiency.
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
But he has also sought to reassure investors that Senegal "will remain a friendly country and a sure and reliable ally for any partner that engages with us in virtuous, respectful and mutually productive cooperation."
After three tense years and deadly unrest in the traditionally stable nation, his democratic victory was hailed from Washington to Paris, via the African Union (AU) and the European Union (EU).
US Secretary of State Antony Blinken on Monday spoke with the president-elect by telephone and "underscored the United States' strong interest in deepening the partnership" between their two countries, the State Department said.
On the international stage, Faye seeks to bring military-run Burkina Faso, Mali and Niger back into the fold of the regional Economic Community of West African States (ECOWAS) bloc.
