Zaneta Pasevica was last seen at her home in Arneside Crescent, Morecambe at around 8.20 pm.
She is described as white, five feet nine inches tall, slim build and was wearing a tight-fitting green top and blue jeans. She also had a green pendant around her neck, possibly heart shaped.
Officers investigating believe she could be with her ex-partner, 48-year-old Sukhdev Dhami.
DCI Becky Smith said: “We are growing increasingly concerned about Zaneta and I would appeal to anyone who sees her, or knows where she may be, to get in touch.
“I would also urge Zaneta herself to contact us if she sees this appeal.”
Anyone with information should contact police on 101 quoting log number 1228 of January 27.