Joseph Alexander Daul managed a small family farm, then he became active in the agricultural trade union movement, through the Centre National des Jeunes Agriculteurs (CNJA - National Centre for Young Farmers). He completed his professional training and general education and in 1976 he was appointed national Vice-Chairman of the CNJA with responsibility for European affairs. Daul also became a member of the Committee of Professional Agricultural Organisations (COPA) and of the European Economic and Social Committee in Brussels.
Between 1999 and 2009, Daul was member of the European Parliament. During that period, he was member, member of the Bureau and Chair of the Group of the European People's Party (Christian Democrats) and European Democrats; Chair, Vice-Chair and member of the Committee on Agriculture and Rural Development, Chair and member of the Conference of Committee Chairs, member of the Delegation for relations with Canada, member of the Delegation to the EU-Latvia Joint Parliamentary Committee, member of the Delegation to the ACP-EU Joint Parliamentary Assembly, member of the Conference of Presidents, member of the Committee on Fisheries.
On 12 November 2013, Daul was elected president of the European People's Party. He decided not to run again in the European elections in 2014 and to leave his position as Chairman of the EPP Group in the European Parliament, in order to dedicate all his time to his new function. He was re-elected as President of the EPP at the Madrid Congress in October 2015.
Daul is an "Officier de la Légion d'Honneur", "Chevalier de l'Ordre National du Mérite" and "Officier du Mérite Agricole".