Teenage girl missing from Sydney's northern beaches

Police are calling for assistance from the public to locate a teenage girl who was last seen in the northern beaches on Wednesday.

Lily McElligott, 16, was last seen at her home in North Manly but has not made contact with friends or family since then, which has been reported as out of character.

A police spokeswoman said Lily remained missing on Saturday morning.

"Lily’s family, and officers from Northern Beaches Police Area Command, have serious concerns for her well-being due to her young age and a medical condition requiring treatment," according to NSW Police.

She has been described as being 167 centimetres tall and of Caucasian appearance, with green eyes and shoulder-length brown hair tied in a ponytail.

She was last seen carrying a maroon-coloured backpack and wearing a maroon and grey-striped rugby polo shirt and grey shorts.

Anyone with any information related to the incident is urged to call Manly Police or Crime Stoppers on 1800 333 000.