Brisbane police say a girl, 15, who was missing for about 18 hours has been found safe and well.

A 15-year-old girl who went missing in south Brisbane has been found.

Police say the girl disappeared after being seen at a bus stop in Carindale about 3.20pm (AEST) on Wednesday.

Concerns were held for her welfare as her disappearance was out of character.

But the girl was found safe and well at 9am on Thursday, about 18 hours after she was last seen.