Abdelmadjid Tebboune, 74, campaigned as a technocrat who had proven his integrity by being sacked for falling out with powerful business tycoons after just three months serving as prime minister in 2017 under veteran ruler Abdelaziz Bouteflika.
Tebboune called on Friday for a dialogue with the opposition protest movement, saying at a news conference he would start consultations on a new constitution to be approved by referendum and extended his hand to them “to open a new page”.
But the protesters marching in Algiers quickly rejected his victory.
Thousands crowded central Algiers despite a heavy police presence, suggesting the new leader may struggle to quell the uprising that ended Bouteflika’s two-decade rule in April.
According to official results, Tebboune won the election with more than 50% of the vote, avoiding the need for a run-off against any of four other senior former officials sanctioned to stand.
Authorities said turnout was 40%.