Trinity Everitt, also known as Alex Paige, was reported missing after leaving home at 5pm on Tuesday, May 19.
The 15-year-old is known to frequent Doncaster town centre.
She is white, 5ft 2ins tall, of a slim to medium build and has a shaved head with a small amount of black and red hair on top.
Trinity was last seen wearing a black jumper, black jeans and had a grey bag.