[7][8] In 2008, Quatennens received a baccalauréat in economic and social affairs from the Catholic school La Croix Blanche in Bondues.

[11] Adrien Quatennens became a follower of Jean-Luc Mélenchon in 2008, joining him in the Left Party (PG) in 2013 and becoming a member of its national council two years later.

[17] Quatennens was nominated by LFI in Nord's 1st constituency during the 2017 French legislative elections, winning 19.38% of the vote in the first round against 32.61% for Christophe Itier of La République En Marche (LREM).

[24][25] Quatennens' early days in the National Assembly attracted much media attention,[13][24][26][27][28][29] especially after he gave a speech lasting half an hour on 10 July 2017.

He denounced the proposal as an "inequitable" project due to differences in life expectancy between social classes as well as its ultimate goal of effectively raising the retirement age.

[36] Quatennens was one of the French political figures targeted by Pegasus spyware under the orders of the government of Morocco, leading him to file a legal complaint in court.

In his teenage years, Quatennens also became a fan of Nirvana, Noir Désir, Bob Marley—of whom he wrote a biography at the age of 12—and Hubert-Félix Thiéfaine, whose concerts he has attended many times.