Police and the family of Yvonne Hegarty are appealing for information about her whereabouts.
A post on PSNI Facebook says: "Mrs Hegarty was last seen at 5pm on Monday the 25th of June 2018 and her family and friends are very concerned for her wellbeing."
The Coleraine woman is described as 5ft 2ins tall and slim with blonde hair.
She is 50-years-old.
"If anyone has seen this lady or has any information leading to her safe return however small please do not hesitate to contact ourselves on 101 quoting reference number 1680 of the 25th of June," adds the post.