After graduating from the Sapienza University of Rome in Economics and Commerce, he began working at the CGIL study office, and always kept on a socialist level.
In 1997, he left both the RAI board of auditors and the Department of Economic Affairs of the Presidency of the Council of Ministers, working as a City Manager of Milan, whose mayor was Gabriele Albertini.
In 2016, he ran for the post of mayor of Milan from the centre-right coalition supported by Silvio Berlusconi, Matteo Salvini, Maurizio Lupi, and Albertini.
In January 2018, Parisi became the president of Lazio candidate with the centre-right coalition;[2] His principal opponents were the incumbent president Nicola Zingaretti (centre-left coalition), the outgoing deputy Roberta Lombardi (Five Star Movement), the incumbent Amatrice mayor Sergio Pirozzi (supported by Gianni Alemanno and Francesco Storace), and the CasaPound candidate Mauro Antonini.
On 4 March 2018, per the Tatarella Law of 1995 still in force, Parisi became regional councilor and the leader of the opposition he arrived second in the electoral race of presidential candidates, with 31% of the votes.