The woman, from Bingley, was trying to get into a taxi when she was assaulted by an unknown man and woman.
The man pushed her while the woman punched her in the face, causing her to fall against the wall during the incident outside Leeds train station in the early hours of Sunday, March 13.
Whilst the victim was on the floor, the woman kicked her and threw the victim’s mobile phone at the man she was with, smashing it on the ground.
The couple both left in a taxi heading to the South Parkway area of Seacroft.
Police have issued CCTV images of two people they are keen to trace in connection with the incident.
PC Dan Worthington said: “The victim was taken to hospital where she is still undergoing treatment for a nasty cut on her head.
“This was completely unprovoked and violent behaviour displayed by both the man and woman involved.
“This is totally unacceptable conduct and it is vital that we trace the people responsible and bring them to justice.
“We believe the man and woman pictured may be able to help with our enquiries. If you recognise them please contact us”
Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or Crimestoppers anonymously on 0800 555 111.