Daphne Filippaki has studied at the Faculty of Law of the National and Kapodistrian University of Athens and holds the postgraduate diploma (M.Sc) "Environment and Development" of the National Technical University of Athens. She is a Court of Appeals Lawyer (in suspension) at the Athens Bar Association. 

From 1998 to 2003, she worked as a lawyer and legal advisor to construction and media companies. In July 2003 she joined the Ombudsman's staff, dealing with issues of environmental protection (natural, urban, cultural), urban and spatial planning, public works and culture. From September 2019, until her appointment as Deputy Ombudsman, she was a legal advisor to the Deputy Minister of Digital Governance, responsible for simplification of procedures.

She has published in scientific journals and has participated in scientific conferences. She has participated as an expert in European Commission twinning programs. She served as General Secretary of the Board of the Hellenic Environmental Law Society (October 2010 - February 2015). She is a member of the trainers registry of the National Center for Public Administration and Local Government and participates in its training programs.

She speaks English, French and German.