Kathleen Ritchie from Glenrothes, was last spotted in the Annandale Gardens area of the town on 21 May at about 8.20pm.
Police have issued an appeal for information on her whereabouts.
She has been described as "being 5ft 5ins tall, of a slim build and fair complexion with long fair or blonde hair” and was last seen wearing a red jacket, blue jeans and carrying a pink handbag.
Sergeant Paul Thomson said: “Along with her family, we are becoming increasingly concerned for Kathleen’s welfare and are keen to find her as soon as possible.
“I would urge anyone who may have information about her whereabouts or who may have seen her to contact us immediately.”
Sergeant Thomson added: “Similarly, if Kathleen is reading this, let us know you are safe and well.”
Police have asked that anyone with information contact them on 101 quoting reference number 3547 of 21 May 2021.