After graduating from the Ecole Centrale de Marseille, Frank Lacroix began a long career in the energy sector, during which time he was Chairman and CEO of the Dalkia group from 2011 to 2014 and a member of the Executive Board at Veolia where he held the position of Senior Executive Vice-President in charge of Energy Services. He was successively appointed Director of the Low Current and Public Lighting business, Director of regional operations, Technical and Operations Director and CEO of French operations of the Dalkia group.

In July 2014, he joined the EDF group and successively held the positions of Deputy Director of R&D then Director of European Operations within the International Department. Since May 27, 2019, he has been a member of the board of directors of Albioma, an independent producer of renewable energy.

He served as CEO of SNCF's TER activity from 2016 to 2020, before joining the Elior Group in February 2021 as Chairman and CEO of Elior Services.