Police are appealing for public assistance after a 15-year-old girl went missing in Sydney's eastern suburbs on Friday afternoon.

Bronti Cuello was last seen at 4pm on Friday at a house on Bondi Road, Bondi.

Police were contacted just after midnight on Saturday when she failed to return to that address. Police and family both hold concerns for the girl's welfare.

Bronti is described as being of Mediterranean appearance, about 140cm to 150cm tall, with a thin build and black hair.

She was last seen wearing khaki tracksuit pants and a cropped grey jumper.

She is known to frequent the Bondi, Bondi Beach and Mascot areas.

Anyone with information about Bronti's whereabouts is urged to contact Crime Stoppers.