The actor left France after a public disagreement with authorities over plans to raise taxes.
"The French betrayed me and I consider myself practically Russian," he said at the Moscow International Film Festival. "My heart is Russian-French."
The "Cyrano de Bergerac" actor gave praise to Putin during the news conference.
"[He] has a very strong personality; he is exactly the kind of leader Russia needs at the moment," Depardieu said.
The actor was at the film festival to promote his new movie, "Rasputin," in which he plays the titular Russian character, RIA Novosti reported.
Depardieu said he gave his script to Putin to check for distortions of Russian history and it received the president's seal of approval.