West Goshen Township police say Dunn and a passenger in his 2007 Porsche died early Monday after the car left the roadway and burst into flames. The crash occurred near the Philadelphia suburb of West Chester.
Authorities say speed may have been a factor.
Dunn appeared on the MTV show that ran from 2000 to 2002 and its three big-screen adaptations. Most recently, he hosted "Proving Ground" on the G4 cable network.
A phone message left for Dunn's manager wasn't immediately returned.
Police say the passenger must still be identified.