Summer Townend was reported missing from home yesterday afternoon.
Officers say they are concerned for her welfare.
Summer is described as white, about 5ft 6ins tall and of medium build, with long blonde hair, which was worn in a bun when she was last seen.
She was wearing a rust-coloured quilted jacket with a fur-trimmed hood, white shirt, black leggings, and black Dr Marten type shoes.
She was carrying a black school bag, which is believed to have contained a change of clothing.
She has links to Willesborough, in Ashford, Kent, and to Coventry and Manchester.
Anyone who has seen her or who has any information that could assist in tracing her is asked to contact West Yorkshire Police via 101 quoting log number 1423 of December 3.