The actor unveiled himself as one of the Jamaican reggae artist's biggest fans, and shared his appreciation for Paul's ability to "make every song better".
His admission came when he and his "Spider-Man: Far From Home co-star Tom Holland sat down for an BBC Radio 1 interview with host Greg James, where they played a game called "Unpopular Opinions" in which listeners call in to submit their thoughts.
When listener Brandon proclaimed that "Sean Paul is massively overrated," Gyllenhaal was incredulous.
"Sean Paul makes every song better that he's in," he insisted, defending the dancehall star. "He's a genius. There's not a song he's on or a remix that he's on that isn't good."
Paul has contributed vocals to some of the pop world's biggest hits, including Beyonce Knowles's 2003 song "Baby Boy", David Guetta and Becky G's "Mad Love", Sigala, Kent Jones and Fuse ODG for "Feels Like Home" and recently joined Idris Elba, Wiley, and Stefflon Don on single "Boasty".
"There's not a moment he comes on the radio where you're not like, 'Come on'," he gushed. "He makes driving fun. You could be stuck in traffic and he comes on and you want to dance. It doesn't matter."
Due to Gyllenhaal's stong defence of the 46-year's old musical output, James suggested they end the chat by playing a Sean Paul song of the Hollywood star's choice.
The 38-year-old chose Sia Furler's "Cheap Thrills", applauding the dancehall artist for "killing every empty beat" with his ad libs.