Born in 1957 in Athens (Greece), Mr Dimitrios Gratsias obtained his master’s degree in law from the Ethniko kai Kapodistriako Panepistimio Athinón (National and Kapodistrian University of Athens, Greece) in 1980 and a diplôme d'études approfondies (diploma of advanced studies, DEA) in public law from the université de Paris I, Panthéon-Sorbonne (University of Paris I, Panthéon-Sorbonne, France) in 1981. The following year, the Centre universitaire d'études communautaires et européennes (Université Paris I) (University Centre for Community and European Studies, University of Paris I, France) awarded him a diploma in Community law.

In 1985, Mr Gratsias began his professional career at the Symvoulio tis Epikrateias (Council of State, Greece) where he worked as a junior officer until 1992. He was subsequently appointed as a junior member in 1992 and then as a member in 2005. In addition to those functions, he was appointed, in 1998, as a supplementary member of the Anotato Eidiko Dikastirio (Superior Special Court, Greece) for two years (1998-1999) and, in 2006, as a member of the Eidiko Dikastirio Agogon Kakodikias (Special Court for Actions against Judges, Greece) for one year. In 2008, he was a member of the Anotato Dikastiko Symvoulio Dioikitikis Dikaiosinis (Supreme Council for Administrative Justice, Greece). During the 2009-2010 judicial year, he was an inspector of administrative courts.

Between 1994 and 1996, Mr Gratsias joined the Court of Justice as a legal secretary in the cabinet of Advocate General Georges Cosmas.

Mr Gratsias was a Judge at the General Court between 25 October 2010 and 6 October 2021 where he also took on the functions of President of Chamber for two successive terms, from 18 September 2013 to 30 September 2019. He has been a Judge at the Court of Justice since 7 October 2021.