Police are appealing for information on the whereabouts of Catriona Elizabeth Smith.
The 19-year-old was last seen on Thursday, September 5, wearing a dark purple hoody with blue denim shorts and blue trainers.
She is 5ft tall and has short hair and hazel coloured eyes.
She was seen by her mother leaving her home in Dunmore Close, Lincoln, at around 6.30am that day.
Anyone with any information should call 101 as soon as possible.