|Alma mater||École Polytechnique, ÉNA|
|Occupation||Chairman of Engie|
After his studies, he joined the Treasury. From September 1982 and July 1984 he was the technical advisor in charge of industrial affairs under the Minister of Economics and Finance (during the time of Jacques Delors)
In 1984, he started working as a special advisor for Suez, known today just as Suez. He has been its Chairman and CEO since 2001.He was named Deputy Delegate General for Industrial Affairs in June 1986. In July 1987, he was General Director of the European Court of Human Rights, an affiliate of the Compagnie financière de Suez. In January 1991 he started as the Deputy Director General of the company, but a month later he became the Managing Director and Chairman of the Management Committee of the Société General de Belgique, to ensure its refocusing and development.
He was appointed as a member of the Hong Kong Chief Executive's Council of International Advisers in the years of 1998-2005. He is the President of Paris Europlace. He is also the President of the Fondation Agir Contre l'Exclusion (FACE).
In 1995 he took a position as the head of Suez and since then he has worked for Suez while focusing on three businesses: energy, water, and waste  He was also the instigator of the reconciliation between Suez and the Lyonnaise des Eaux. The Suez-Lyonnaise des Eaux was started in 1997, at which time Mestrallet became the chairman of its executive board while Jérôme Monod, chairman of Lyonnaise, became the Chairman of the Supervisory Board. However, the group soon went back to its original name, Suez and in 2003 its leaders made a proposition to shareholders to change the association of the company by becoming an LP with a board of directors and Gerard Mestrallet as the CEO.
in July 2008, he was appointed CEO of Engie.
In 2014, his retirement cap of 21 million euros was a controversy in the media due to GDF-Suez’s record losses for 2013 and its effort to prepare a savings plan.
- Chairman of the Board of Suez Environment
- Member of the Board of Directors of Société Générale
- Member of the European Round Table of Industrialists (ERT)
- Member of the Supervisory Board of Siemens
- Member of the Board and Advisory Council of the "Institut de l'entreprise".
- President of the Mayor’s Council of Chongqing since 24 September 2006.
- Member of the Mayor's Council of Shanghai
- Member of the Mayor's Council of Beijing
- Member of the Council of International Advisers to the Hong Kong government
- Member of the board of trustees of the University of Tongji (Shanghai)
- Member of the International Council of JP Morgan Chase
- President of the Policy Board of Paris Europlace (since 2003), member of the Council of the French Institute of Administrators.
- President of the "Fondation Agir contre l'exclusion".
In May 2016, Engie announced that Gérard Mestrallet's 350,000 euro chairman salary will go to the Engie foundation charity and that he will carry out his new job for free.
He is Commander of the National Order of the Legion of Honour and is a Knight of the National Order of Merit.
He is the son of Georges Mestrallet and Paule Mestrallet-Besnard. He has two brothers, Michael and Patrick Mestrallet. He married Joëlle Emillienne Renée Arcens in 1974 and has three children.
- "Engie press release" (PDF). Engie.com. Retrieved 3 May 2016.
- "GDF board biography". Gdfsuez.com. Retrieved 12 July 2013.
- "List of Public Companies Worldwide, Letter - Businessweek - Businessweek". Investing.businessweek.com. Retrieved 31 July 2015.
- "Gerard Mestrallet". DIRIGEANTS ENTREPRISE. Retrieved 24 October 2014.
- "Hong Kong". Info.gov.hk. 6 November 2003. Retrieved 12 July 2013.
- "FACE leadership". Fondationface.org. Archived from the original on 2 February 2013. Retrieved 12 July 2013.
- "Gerard Mestrallet". Fondationface.org. Retrieved 24 October 2014.
- "Polémique autour de la retraite-chapeau du PDG de GDF Suez". Le Figaro. Retrieved 24 October 2014.
- Isabelle Kocher to Head Engie, Inti Laundauro, Wall Street Journal. Retrieved January 14, 2016
- "Organisation de l'Institut | Institut de l'entreprise" (in French). Institut-entreprise.fr. Retrieved 31 July 2015.
- Les salaires des patrons du SBF 120, Le journal du net, 25 juin 2013
- Classement : les salaires des patrons du CAC 40, Challenges, 3 mai 2013
- Engie says Mestrallet's chairman salary will go to charity, Reuters, May 3? 2016
- "Décret du 2 mai 2012 portant promotion et nomination" (in French). Legifrance. Retrieved 31 July 2015.
- "Gérard Mestrallet 1949— Biography - Education and early career, Suez begins a transformation, Purchases nalco". Referenceforbusiness.com. Retrieved 31 July 2015.
| CEO of Engie