Lagarde takes over duties as European Central Bank head
"She was appointed by the European Council on 18 October 2019 for a term of office of eight years," the ECB said in a statement.
Lagarde succeeded Mario Draghi, who was president of the ECB from 2011 to 2019.
Lagarde, 63, holds a law degree from the Paris Nanterre University and a master's degree from the Political Science Institute in Aix en Provence, southern France.
In 2011, Lagarde was elected to become the first-ever female head of the International Monetary Fund (IMF).