The unidentified victim was discovered when firefighters extinguished the blaze near the Fantasia Gardens miniature golf course.
Deputies were called to the scene at 1209 Epcot Resorts Boulevard to assist the Reedy Creek Fire Department at 4.11am on Saturday morning.
"Reedy Creek Fire Department extinguished the fire and discovered a victim deceased inside the vehicle," said a spokesperson for the Sheriff's Office.
"Fire Marshall, Homicide, and Sector 6 Investigators are on scene conducting an investigation.
"The investigation is ongoing. We will provide information as it becomes available."