The girl was walking along St Mary's Road, just off Sticker Lane, at around 11.10pm on March 25, when the man approached her.
He grabbed the victim, kissed her, and then pulled her into a nearby garden where he sexually assaulted her.
The girl managed to get away and run home before calling the police.
West Yorkshire Police have issued a picture of a man they want to speak to in connection with the assault who they believe was in the area at the time.
Anyone with information or who recognises the man in the picture is urged to call police on 101, quoting crime reference number 13210149722.