Jessica Richardson, 12, was last seen on All Saints Road, Woodlesford, at about 8am today (Thursday).
Detective Inspector Fiona Gaffney, of Leeds District CID, said: “We are very concerned for Jessica’s welfare given her young age and we urgently need to trace her and check that she is okay.
“We have officers out looking for her and would like to hear from anyone who has seen her or who has any information that could assist in tracing her.”
Jessica is described as white, about 5ft tall, with long mousy brown hair.
She was last seen wearing a black waist-length puffer jacket, black trousers and a white shirt.
Anyone with information is asked to contact officers via 101, quoting log number 337 of January 25.