British Transport Police (BTP) released images of a man following reports of the robbery at about 7.50am on Thursday 19 January.
The force said the victim went by herself to the women’s bathroom located near platform one.
Shortly after a man followed her in, hit her on the head causing her to fall to the floor, before stealing her headphones.
The man fled the station vanishing through the Hudson’s place exit.
A BTP spokesman said: “Officers would like to speak to the man in the images who may have information that could help their investigation.”
Anyone who recognises him is asked to contact British Transport Police by texting 61016 or by calling 0800 40 50 40. In both cases, quote reference number 328 of 19/01/23.
Alternatively, call Crimestoppers anonymously by calling 0800 555 111.