Kaci Foster, 16, from Scarborough didn't return home on Wednesday June 8.
Kaci is described as being around 5ft 9ins tall, with dark hair, and is possibly wearing a black tracksuit, and is believed to be in the Scarborough area.
Officers are concerned for her safety.
If you have seen Kaci or have any information about where she is, call 101 and select option 1 to speak to the Force Control Room.
Quote reference NYP-08062022-0316 when sharing information.