Kasey Christie, 16, was last seen in Worthing in the early hours of Saturday morning (May 25).
She is white, 5’ of small build, with long blonde hair and was last seen wearing black coloured clothing.
Police are urging Kasey to make contact with either an officer or a responsible adult. There are concerns she may require medical treatment.
Kasey has links to Chichester, Worthing and Billingshurst.
Please dial 999 if you see Kasey. If you have seen her since the last sighting or believe you know where she could be please report online quoting 1580 of 22/05.