After being admitted to the Paris Bar, she joined the international law firm Baker & McKenzie as an associate in 1981, specializing in labour and anti-trust, as well as mergers and acquisitions.

[20][21] During her year in the United States, Lagarde worked as an intern at the U.S. Capitol as Representative William Cohen's congressional assistant, helping him correspond with French-speaking constituents from his northern Maine district during the Watergate hearings.

[26] She handled major antitrust and labour cases, was made partner after six years and was named head of the firm in Western Europe.

[43] U.S. Treasury Secretary Timothy Geithner said that Lagarde's "exceptional talent and broad experience will provide invaluable leadership for this indispensable institution at a critical time for the global economy.

Oxfam, a charity working in developing nations, called the appointment process "farcical" and argued that what it saw as a lack of transparency hurt the IMF's credibility.

[44] On 17 December 2015, Michel Sapin, French Finance Minister, said that Lagarde could stay on as head of the IMF, despite being charged with criminal negligence.

[48] Lagarde paid a courtesy call on Malaysian Prime Minister Mahathir Mohamad at the sidelines of the 33rd Asean Summit in Singapore.

She also said, "we had essentially a trillion dollars on the table to confront any market attack that would target any country, whether it's Greece, Spain, Portugal, or anybody within the eurozone."

"[50] In public remarks made right after her appointment, Lagarde stated that both the IMF and EU required Greek austerity measures as a prerequisite for further aid.

She said, "If I have one message tonight about Greece, it is to call on the Greek political opposition to support the party that is currently in power in a spirit of national unity.

"[41] On 25 December 2011, Lagarde argued that the world economy was at risk and urged Europeans to unify in terms of the debt crisis facing the continent.

[51] In July 2012, as the Greek economy continued to decline, and the country's leaders asked for an easing of the terms of external assistance, Lagarde said she was "not in the negotiation or renegotiation mood at all.

[54][55] According to Yanis Varoufakis, the combative former Finance Minister of Greece, Lagarde and others at the top of the IMF were quite sympathetic behind closed doors, while stating that inside the Eurogroup there were "a few kind words and that was it".

"[63][64] In an effort to quell the negative response, the next day Lagarde made a post to her Facebook page saying: "As I have said many times before, I am very sympathetic to the Greek people and the challenges they are facing.

[63] In response to Lagarde's belief that not enough Greeks paid their taxes, Professor Emeritus John Weeks of the University of London said, "The moral weight of Christine Lagarde's matronising of the Greeks to pay their taxes is not strengthened by the fact that, as director of the IMF, she is in receipt of a tax-free annual salary of $468,000 (£298,000, plus perks).

The loan, then the largest in the Fund's history, sparked controversy within the financial institution, as such a sum was far too high for such an economically fragile country.

[72] In September 2019 writers for Bloomberg opined that as president Lagarde was expected to maintain the accommodative monetary policy of her predecessor, Mario Draghi.

By contrast, the Banque de France governor François Villeroy de Galhau (and member of the ECB’s governing council) was supportive,[78] as well as an open letter whose 164 signatories included academics, economists, trade unions and environmental activists and 62 organizations like Greenpeace and Attac, who characterized the plan for the ECB to purchase financial instruments of the fossil fuel industry as "particularly shocking" .

"[82] In September 2024 Lagarde announced that the ECB's primary interest rate would be cut to 3.5% because of weak eurozone growth, following of dropp of inflation to 2.2%.

[90] On 28 October 2012, Greek reporter and editor Kostas Vaxevanis claimed to be in possession of the list and published a document with more than 2,000 names in his magazine Hot Doc.

A few days before the Greek general elections of January 2015, when it was clear that left-wing Syriza would come to power, the financial crimes police of the conservative government of Antonis Samaras shredded reams of documents pertaining to corruption cases.

[96] On 3 August 2011, La Cour de Justice de la République, a special court in France set up to judge ministers and public officials for alleged crimes committed while in office, ordered an investigation into Lagarde's role in a €403 million arbitration deal in favour of businessman Bernard Tapie when she was finance minister in 2007.

[98] On 24 May 2013, after two days of questioning at the Court of Justice of the Republic (CJR), Lagarde was assigned the status of "assisted witness", meaning that she herself was not under investigation in the affair.

Christine L."[102] Subsequently, in August 2014 the CJR announced that it had formally approved a negligence investigation into Lagarde's role in the arbitration of the Tapie case.

[60] Lagarde was portrayed by Laila Robins in the HBO television film Too Big to Fail (2011), which was based on the popular non-fiction book of the same name by The New York Times journalist Andrew Ross Sorkin.

[110] Meryl Streep based parts of Miranda Priestly's appearance in the feature film The Devil Wears Prada (2006) on Lagarde, citing her "unassailable elegance and authority".