He was the author as of June 2007 of eight books and many more articles on political science, and a contributor to the magazine Sfera Politicii.

Barbu was born in Bucharest, and graduated from the Nicolae Bălcescu High School (the present-day Saint Sava National College) in 1976.

He was appointed to the scientific board of the Institute for the Investigation of the Crimes of Communism and the Memory of the Romanian Exile in 2014.

In 2004, the European Anti-fraud Office (OLAF) notified the Romanian Government about irregularities found in a Phare program headed by Barbu, as Dean of the Faculty of Political Science.

[2] According to both sources, the program engulfed over 200,000 euros coming from PHARE TEMPUS grant money into civil servant training courses which never took place and which had nonexistent people enrolled.

In an interview during the 2012 parliamentary election campaign, as candidate from the Social-Liberal Union, Daniel Barbu dubbed the event as a misunderstanding and a "no penal matter".

The National Council for Combating Discrimination launched an inquiry and Crin Antonescu, leader of PNL and President of the Senate, demanded Barbu's resignation, which he submitted on 12 December 2013.

He resigned from that position in order to run for the 2019 European Parliament election on the Alliance of Liberals and Democrats's (ALDE) list.