Elle Marshall, who is from Inverkeithing, was last seen at 2:30pm on Monday 1 July in the area of Links Street, Kirkcaldy and has not been seen since.
Police have said they are increasingly concerned for Elle's welfare and are desperately seeking any information relating to her whereabouts.
Elle is described as white, 5 foot 8 inches tall, of slim build, with long brown hair. The clothing she is wearing is unknown.
Sergeant Katie Blackwell of Dalgety Bay Police Station said: “Elle has been reported missing to police and we are becoming increasingly concerned for her. She is known to have links in both the South West Fife and Kirkcaldy areas.
“I would urge anyone who may have seen Elle or knows where she is to please contact police immediately.”
“If Elle reads this appeal, I too would ask that she gets in touch with Police or her family to let us know that she is safe.”
Those with information can contact Dalgety Bay Police Station via 101, quoting incident number 3350 of 4th July, 2019.