Troopers were called to the crash on KY 519 in West Liberty just before 10 p.m.
They said James D. Lewis, 30, was driving an ATV on his property with his 5-year-old son when Lewis tried to climb an embankment.
Troopers said he lost control of the ATV, throwing both him and his son, and trapping Lewis underneath.
The Morgan County coroner pronounced him dead at the scene. His son was transported to the hospital with minor injuries.
Troopers said neither Lewis or his son were wearing helmets during the accident.