Shain Gandee, 21, was found dead in a car along with two other men including his uncle David on Monday morning in Sissonville, Kanawha County, a spokeswoman for County Commissioner Kent Carper told Reuters.
"This is a very sad and tragic event. We live in a very small community. Our thoughts and prayers are with the Gandee family," Carper said in a statement.
Gandee was one of the lead cast members of "Buckwild," which follows a group of young adults living in rural West Virginia and has attracted some criticism for its portrayal of the cast's hard-partying ways.
Gandee was often seen on the show "four-wheeling" in his truck, driving in circuits on off-road terrain.
The Kanawha County Sheriff's Department did not release any information on the cause of death, saying it was investigating.
But the department had earlier issued a missing persons alert for Shain and David Gandee, who family members said were last seen at a local bar in Sissonville at about 3 a.m on Sunday.
"The two said they were going four-wheeling in Shain's Ford Bronco. No one knows where they planned to ride, or the direction in which they left," the sheriff's department said in its missing persons statement, adding that foul play was not suspected.
MTV said it was "shocked and saddened" by Gandee's death. "Shain had a magnetic personality, with a passion for life that touched everyone he met and we will miss him dearly," MTV said in a statement.