The 37-year-old Cloutier made the announcement in his riding of Lac-Saint-Jean in the Saguenay region north of Quebec City.
Cloutier was first elected to the legislature in 2007 and served as Canadian intergovernmental affairs minister in Pauline Marois's minority government between 2012 and last April.
He joins former cabinet colleagues Bernard Drainville and Martine Ouellet in the race.
The other declared candidate is Pierre Cere, a spokesman for a group that represents the unemployed.
Cloutier is a lawyer by training.
Media magnate Pierre Karl Peladeau has not yet confirmed whether he will run, although he is considered the likely front-runner if he does seek the leadership. Candidates have until Jan. 30 to enter the race.
Another possible candidate, Jean-Francois Lisee, said Monday he will make a decision soon on whether to run.
Also on HuffPost