The crash happened just before 7 p.m. Friday on the Harnett Dunn Highway (Highway 55).
Troopers said the car was traveling north when it ran off the road, hit a ditch and flipped several times into a field.
The 3-year-old was pronounced dead at Betsy Johnson Hospital. Two adults and another child were also in the car and taken to WakeMed.
There is no immediate word on their conditions.