Ibrahim Boubacar Keita has been sworn in as Mali's new president at the Supreme Court in the capital, Bamako.
Before he took his oath of office, transitional leader Dioncounda Traore handed over power at a ceremony inside the presidential palace.
Mr Keita, a former prime minister, won last month's run-off election.
The election of the new president is intended to restore normality after a coup and French-led military action against Islamist rebels in the north.
France sent more than 4,000 troops to Mali in January and together with West African troops regained control of towns and cities from groups aligned with al-Qaeda.