The Department of Public Safety says the accident happened Monday morning near Springtown, about 20 miles northwest of Fort Worth.
Trooper Gary Rozzell identified the victim as Haven Lee Norton of Springtown.
Rozzell says the Springtown Independent School District bus stopped to pick up some children. The bus was pulling away when the boy tripped and fell as he tried to reach the vehicle. The driver apparently didn't see the boy, who died at the scene after being run over.
Rozzell says the bus had a driver, a co-driver and four children. DPS doesn't believe those students saw the accident.
Springtown ISD officials say counselors are available.