Alexia Boulton-Miller was last seen in the St Peter’s area on the evening of Wednesday 10 April 2024.
It is thought she may have since travelled to the Rainham area.
The 15-year-old is described as around 5ft, 5ins tall, with long brown hair with blonde highlights and brown eyes.
Anyone who has seen her or knows of her whereabouts is urged to call 999, quoting 11-0198.
