In 2017, he was elected a deputy (member of the National Assembly) for the 1st constituency of Nord. He got 50.11 percent of the votes in the second round of the election. He became a member of the Social Affairs committee of the National Assembly. He voted against the 2017 French labour law reform. He wants burnouts to officially become work diseases. Quatennens is also the deputy chairman of the France–Greece and France–Denmark friendship groups of the National Assembly.