Police are seeking urgent public assistance to locate a missing 14-year-old Indigenous girl who was last seen in Brisbane City on Sunday.

The girl was last seen on William Street around 4pm and has not been seen of heard from since.

Police hold concerns for her welfare as she suffers from a medical condition that requires medication.

The girl is First Nations, approximately 155cm tall, with a larger build and long dark curly hair.

She was last seen wearing a white hoodie with a black "Hoodrich" motif on the front, light blue track pants and black shoes.

Investigators believe the girl may be in the Southport area.

She also frequents the Brisbane City and Springfield area.

Police are appealing to the girl or anyone with information regarding her whereabouts to come forward by contacting police or Crimestoppers on 1800 333 000.

Information is managed confidentially, and the public is reminded not to report information though Queensland Police social media pages.