Edit Herczog graduated from the Russian Teleki Blanka Secondary School in Székesfehérvár in 1979. Herczog also hold a degree in Portuguese language and literature in ELTE and then at the European Business School in 1994. She joined the Hungarian Socialist Workers Party in 1985 and of the Hungarian Socialist Party (MSZP) since 1989. In 1998 and in 2002, she became Parliamentary Representative of the MSZP. Between 1998 and 2002, she worked in the Commissions for Corporate and European Integration Affairs. She served as a member of the Hungarian delegation of the European Commission in 1999.
In 2004 Herczog was elected Member of the European Parliament for Hungary and remained an MP until 2014. During that period, Herczog was member of the Socialist Group in the European Parliament and treasurer of the Group of the Progressive Alliance of Socialists and Democrats in the European Parliament, member of the Committee on the Internal Market and Consumer Protection, member of the Delegation to the EU-Ukraine Parliamentary Cooperation Committee, member of the Delegation for relations with Canada, member of the Committee on Budgets, member of the Delegation to the EU-Armenia, EU-Azerbaijan and EU-Georgia Parliamentary Cooperation Committees, member of the Committee on Industry, Research and Energy and member of the Delegation to the Euronest Parliamentary Assembly.