Jeanette Roche, 47, was last seen at her home address at 4.15pm on Monday June 27.
She is described as white, 5ft tall, slim build with shoulder length dark brown hair.
She was last seen wearing glasses, a coral t-shirt with buttons, navy leggings and black platform trainers.
It is possible that Jeanette may have travelled to Wigan but she also has links to the Leyland and Chorley areas.
PC Dan Gardner said: “We are growing increasingly concerned about Jeanette. I would appeal to anyone who sees her or knows where she might be to get in touch with us. I’d also ask Jeanette herself to contact us if she sees this appeal to let us know she is okay.”
Anyone with information should contact police on 101 quoting log number LC-20160627-1191.