Michaela Edge has been missing from Rowley Regis since 7am on Tuesday.
Police are urgently trying to trace the teenager. Anyone who sees her is urged to call 999.
A spokesman for West Midlands Police said: "Have you seen missing teenager, Michaela Edge? The 13-year-old from Rowley Regis, Sandwell has been missing since 7am on May 11, and we are urgently trying to locate her.
"Michaela is described as approximately 5ft 4ins tall, with shoulder length, dark brown hair. She was last seen wearing black leggings, a black and white checkered hoodie and black Adidas trainers.
"If you see her, please call 999. Alternatively, if you have any information, contact us via live chat on our website or by calling 101."