Officials say 34-year-old Arturo Herrera was driving southbound on Highway 41, south of Hanford Armona Road, when a woman walked across the lanes for an unknown reason.
Herrera tried to stop the truck but ended up hitting the woman, who died at the scene. Her name has not been released.
It's unknown if drugs or alcohol were factors in the collision.
Herrera remained at the scene and cooperated with officers.