Police are looking to make contact with Jade Cavanagh-Smith, 15, who has not been since 6.30pm on Sunday 24 August 2014, when she was in the city centre.
She is described as white, with a slim build and shoulder length dark hair. When Jade was last seen she was wearing denim jeans, a green hooded top and a black jacket.
Officers are concerned for Jade’s welfare due to her age.
It is believed that Jade is still in York.
PC Francis Hawthorn, of York Safer Neighbourhood Team, said: Jade, if you see or hear this appeal, please get in touch with your family as they are concerned about you and want to know that you are safe and well.
If you would prefer to speak with a police officer, then please contact us and we will make sure family know that you are not in any danger.
I am also asking anyone who sees Jade to contact the police straight away.
Anyone who can help locate Jade Cavanagh-Smith should contact North Yorkshire Police on 101, select option 1 and pass the information to the Force Control Room.