Missing, Hannah Stewart: Blue Mountains police are calling for public assistance

Police are appealing for public help to help locate a teenager who has been missing from the Blue Mountains area for three weeks.

Hannah Stewart, 15, was last in contact with her family on June 19, however police were only notified on Thursday, July 9 about her disappearance.

Officers and family have concerns for Hannah's welfare due to her age.

Hannah is Caucasian in appearance with a fair complexion, about 155cm to 160cm tall, of thin build with long red hair.

MISSING: Hannah Stewart, 15, was last seen three weeks ago. Photo: NSW POLICE

MISSING: Hannah Stewart, 15, was last seen three weeks ago. Photo: NSW POLICE

Police believe Hannah may be travelling on the rail network in the areas of Granville and Campbelltown and also frequents Castle Hill.

Anyone with information about Hannah's whereabouts is urged to contact Springwood Police Station or Crime Stoppers on 1800 333 000.