The rapper was a founding member of the hip-hop trio.
The group's rep told CNN that Jolicoeur's death is "a huge loss."
A cause of death was not immediately available, but Jolicoeur revealed in a 2017 video that he'd been diagnosed with congestive heart failure. ET has reached out to the rep for comment.
Jolicoeur teamed up with high school buddies Vincent Manson, who's known as Pasemaster Mase, and Kelvin Mercer, who's known as Posdnuos, to form De La Soul in 1988. Their debut album, 3 Feet High and Rising, was released the next year.
Throughout their career, the group earned six GRAMMY nominations. They came out victorious one time, winning the Best Pop Collaboration with Vocals award in 2006 for "Feel Good Inc," which they performed with Gorillaz.
While fans have long been unable to stream De La Soul's music due to rights disputes, last month, the trio confirmed to Pitchfork that their albums will be available on streaming services beginning in March.
The group's most recent release was 2016's GRAMMY-nominated album And the Anonymous Nobody. They were scheduled to perform three shows in the U.K. in April.
Pharrell Williams posted a tribute to Jolicoeur on Twitter, writing that he's "sending love, light and positive vibrations to his family, The Soul and everyone whose lives have been touched by his existence."
Amanda Seales also expressed her condolences, writing on Instagram, "🙏🏽❤️ to De La Soul's Trugoy the Dove."