British Transport Police have released a CCTV image of a man they want to speak to in connection with the incident.
Police said the man was refused travel from Selby Railway Station because he didn't have the necessary bicycle reservation.
He then became verbally abusive to the Transpennine Express guard, before spitting in his face on the platform.
The incident happened at ar ound 4.30pm on October 26, but police only released details today. ((Nov 20)
If you recognise him, or have any information, contact British Transport Police by texting 61016 or calling 0800 40 50 40 and quote reference 423 of 26/10/18.