At 17, following the death of her father, Ms Lagarde went to study in the US for a year, where she perfected her English.
After graduating from law school in Paris, she obtained a Masters degree from the Political Science Institute in Aix en Provence.
In 1981 she returned to the US, joining the international law firm Baker & McKenzie as an associate, specialising in labour, anti-trust, and mergers and acquisitions (M&A).
Eighteen years later, she became the first female chair of the firm.
Ms Lagarde was appointed France's trade minister in 2005 and, under her watch, French exports reached record levels.
In 2007 she became finance minister, the first woman to hold this post not just in France but in any of the G8 major industrial countries.
Never afraid to speak her mind, she blamed the 2008 worldwide financial crisis partly on the male-dominated, testosterone-fuelled culture at global banks.
One of France's most popular right-wing politicians, in 2009 she came second in a poll carried out by broadcaster RTL and newspaper Le Parisien on the country's favourite personalities, beaten only by singer and actor Johnny Hallyday.
But her popularity has stretched beyond French shores and she is viewed with high regard in the international arena.
Well before she took the helm of the IMF, the Financial Times voted her in 2009 the best finance minister in Europe.
Recently in 2020, she was voted as one of the most powerful women in the world.