In November 2015, President Klaus Iohannis named him prime minister; Cioloș assumed office after receiving approval from Parliament.

[1] While a student, Cioloș belonged to the Romanian Hearth Union’s youth wing; he states that his activities there were of a cultural nature, and had nothing to do with the party's extreme nationalist stance.

[2] He also holds degrees in the economy of agricultural development from the École nationale supérieure agronomique de Rennes and from the University of Montpellier 1, where he respectively earned a master's in 1997 and a doctorate in 2006.

[3] Following the resignation of Decebal Traian Remeș due to a corruption scandal,[8] he was appointed Agriculture Minister in October 2007, serving until the following December, when Tăriceanu's National Liberal Party-led government left office after a parliamentary election.

[11] In October 2009, the Emil Boc government, hoping to secure the Agriculture portfolio in the second Barroso Commission, nominated Cioloș as Romania's EU Commissioner.

[14][15] The British magazine Farmers Weekly considered the nomination "a controversial choice", citing recent mismanagement by Romania of EU funds, but also acknowledged his "broad agricultural experience".

[22] In July 2015, Barroso's successor Jean-Claude Juncker named Cioloș as his special adviser on international food security.

[23] In November 2015, Prime Minister Victor Ponta resigned following protests sparked by a deadly nightclub fire, and President Klaus Iohannis appointed Cioloș as his successor.

[26][27] He considers his two main achievements while in office to have been an increase in transparency, including the online release of salaries and expenditures for public institutions and financing contracts; and a reduction in bureaucracy that involved the elimination of numerous formalities.

[28] Ahead of the 2016 parliamentary election, Cioloș received the endorsement on behalf of the National Liberals (PNL) and of the Save Romania Union (USR), in turn urging voters to back either party.

[34] The following month, Cioloș announced the establishment of the 2020 USR-PLUS Alliance between PLUS and the Dan Barna-led Save Romania Union (USR).

[36] He subsequently became leader of the new Renew Europe political group, having secured support from En Marche, Ciudadanos and parties from Germany and the Netherlands.

[42] That May, he quit USR altogether, citing dissatisfaction with the new leadership, and launched a new party, Renewing Romania's European Project (REPER).