He was the second-last of five children; his father, who fought along with the Italian partisans during the World War II, was a cantoniere, a road maintenance worker who needed to live near the workplace due to service requirements, while his mother was a housewife.

He closely followed with the then General Secretary, Gianni Rinaldini, negotiations for the renewal of the metalworkers' contract in 2009 under the centre-right government of Silvio Berlusconi.

[15] On 25 October, almost one million people took part in a mass protest in Rome, organised by the CGIL in opposition to the labour reforms of the government.

[18][19] In June 2015, Landini launched Social Coalition (CS), a transversal political organization, whose goals were the protection of workers and the middle class.

[20] The organization – which reunited several leftist thinkers, such as the jurist Stefano Rodotà, the Communist politician and medic Vittorio Agnoletto, and the former Potere Operaio leaders Oreste Scalzone and Franco Piperno[21] – never became an official party and was disbanded after few months.

[31][32] During his inaugural speech, Landini strongly attacked the M5S–League government and especially its Interior Minister and de facto leader, Matteo Salvini, denouncing a serious risk of a return of fascism in the country.

[33] On 9 February, CGIL, CISL and UIL protested together in Rome, against the economic measures promoted by Conte's government; more than 200,000 people participated in the march.

[38] On 9 October 2021, the CGIL's national headquarter in Rome was attacked my a mob of members the neo-fascist party New Force, who were protesting against the introduction of a COVID-19 vaccination certificate in Italy.