Alexandru Athanasiu (Romanian pronunciation: [alek'sandru atana'si.u]; born 1 January 1955) is a Romanian politician and jurist.
A former leader of the Romanian Social Democratic Party (PSDR), he is a member of the Social Democratic Party (PSD) since 2001.
Athanasiu served as Prime Minister on an interim basis from 13 December to 22 December 1999, heading the Romanian Democratic Convention (CDR) cabinet after the resignation of Radu Vasile.
On 1 January 2007, with the accession of Romania to the European Union, Athanasiu became a Member of the European Parliament for the PSD (inside the Party of European Socialists).
An author of several scientific works, he is the recipient of a PhD in Law, as well as a professor at the University of Bucharest (since 1999).
In 1995, his volume Legea Asigurarilor Sociale ("The Law on Social Security") received the Romanian Academy's Simion Barnu?iu Award.