Marie Arena was born in Mons (Hainaut) on December 17, 1966. She studied economics at the Catholic University Faculties of Mons. After several years in the FOREM services, she was called in 1999 to work as a consultant in the Cabinet of Minister Michel Daerden, responsible for Employment, Training and Housing.
In April 2000, she became Minister of Employment and Training of the Walloon Government. After the 2003 federal elections, she joined the Federal Government as Minister in charge of the Civil Service, Social Integration, Greater Cities, Equal Opportunities and Intercultural Dialogue.
In June 2004, she was appointed Minister-President of the Government of the French Community, responsible for Compulsory Education and Social Promotion, and Minister of Training in the Government of the Walloon Region.
In March 2008, she joined the federal level to occupy her current ministerial position of Minister of Social Integration, Pensions and Cities. On July 17, 2009, she was replaced by the Van Rompuy government and again became a Member of Parliament. On June 13, 2010, she was elected senator. On May 25, 2014, she was elected to the European Parliament where she is a member of the Group of the Progressive Alliance of Socialists and Democrats.