It happened Saturday evening on Clay Rd. near Fry Rd. in Katy.
According to the Harris County Sheriff's Office, the driver of a black sports utility vehicle struck the child and did not stop.
The boy -- believed to be around 10 years old, officials said -- was airlifted to Texas Children's Hospital and is expected to survive.
Investigators found the SUV about a mile and a half away from the scene. The suspect was brought back for questioning.
No charges have been filed and the accident remains under investigation.