Olivia Wood was last seen at Conisbrough Castle after being reported missing from her home on Castle Hill, Conisbrough, at around 10pm Friday.
Olivia has been described as around 5ft 2ins tall and of small build. She was wearing glasses, a dark coloured hoodie, black skinny jeans and carrying a rucksack.
She has not been heard from since.
If you have information about Olivia's whereabouts, contact police on 101 quoting incident number 1178 of 20 January.