Ben Fayot graduated at the Paris-Sorbonne University. He worked as a French teacher for about 20 years. In 1962 he joined the Luxembourg Socialist Workers' Party (LSAP). He started his political career in 1982 when he became a city councilman in Luxembourg. Between 1984 and 1989 Fayot was member of the Chamber of Deputies. In 1985 was appointed president of his party and remained as a president until 1997.
Between 1989 and 1999, Ben Fayot served as a member of the European Parliament. During that time he was member of the Socialist Group, Vice-Chair of the Socialist Group, Vice-Chair of the Group of the Party of European Socialists, Chair of the Committee on the Rules of Procedure, the Verification of Credentials and Immunities, Vice-Chair of the Committee on Youth, Culture, Education, the Media and Sport, Vice-Chair of the Committee on Culture, Youth, Education and the Media, member of the Delegation for relations with the Gulf States and the Gulf Cooperation Council, member of the Political Affairs Committee, member of the Committee on the Rules of Procedure, the Verification of Credentials and Immunities, member of the Delegation for relations with Ukraine, Belarus and Moldova, member of the Committee on Economic and Monetary Affairs and Industrial Policy and member of the Temporary committee instructed to monitor the action taken on the recommendations made concerning BSE (bovine spongiform encephalopathy).
Ben Fayot is also author of several books on history of socialism in Luxembourg.