De Filippo was born in Sant'Arcangelo, in the Basilicata region, to Nicola De Filippo and Rosa Maria Briamonte, belonging to an ancient family of farmers present in the municipality for centuries as certified by the 18th-century Onciario Land Registry.

His political activity began in the Italian People's Party, the left-leaning legal successor of Christian Democracy, at the age of 26, in the Provincial Council of Potenza; he held the office of provincial health assessor and vice-president of the province of Potenza.

[1] On 24 April 2013, the prosecutor of Potenza arrested two Regional Assessors of the De Filippo Cabinet: the Assessor for Labour Vincenzo Viti (Democratic Party) and the Assessor for Agriculture Rosa Mastrosimone (Italy of Values), as well as the head of the opposition Nicola Pagliuca (The People of Freedom), establishing the prohibition of residence for 11 between councilors and former councilors for embezzlement in the scandal of repayments to regional groups.

[nb 1] On the same day, De Filippo appointed a new cabinet, the third of the legislature, and presented his resignation as president of the region.

[2][3] In January 2015, due to the illicit repayments obtained between 2009 and 2010, De Filippo was sentenced by the Court of Accounts of Potenza to "compensate the damage produced to the Basilicata Region" for the amount of €2,641.52.

[7] De Filippo has been married since 1988 to Rosa Tutino, with whom he has two children: Valentina and Nico, born in 1990 and 1993, respectively.