The victim, a 19-year-old woman from Leeds, was approached by the man at 5.10pm on Sunday, May 21.
He racially abused her and punched the left hand side of her face, before leaving the station and walking towards Boar Lane.
Detective Inspector Mick Jackson said: “This was a totally unprovoked and violent attack which has left the victim with bruising and swelling to the left hand side of her face.
“I would like to speak to the man captured on CCTV in connection with this assault. Who is he? If you know him please contact us.”
Anyone with any information is asked to contact British Transport Police on 0800 40 50 40 or text 61016, quoting reference of 220 of 26/05/2017.
Information can also be passed anonymously to Crimestoppers on 0800 555 111.