Emergency services were called to Stourport Road, at around 3.10pm on Thursday.
West Mercia Police is appealing for anyone who witnessed the collision to come forward.
A spokesman for the force said: "The incident happened at around 3:10pm this afternoon in Stourport Road, in Kidderminster, after a young child was injured in a collision with a car.
"The child has been taken to hospital with potentially life-changing injuries. The road remains closed at this time and we are grateful for the public’s patience."
Anyone with information is asked to call West Mercia Police on 101, quoting incident number 00408 of October 1.
Alternatively, contact Crimestoppers anonymously on 0800 555111 or at crimestoppers-uk.org