A 'trespass incident' that began at around 7.15am has put the entire station in lockdown and blocked all lines.
Follow the latest updates via our live blog HEREWhat do police say?
Statement from BTP as of 9.25am: "At 7.03 officers were called to Leeds Station following concerns for a person in a precarious position.
"Officers are on the scene and working to bring this incident to a safe resolution as soon as possible.
"Rail services are currently disrupted. Passengers are advised to check with National Rail services before travelling."
Which trains are affected?
Trains on all lines - including Northern, Transpennine, LNER and CrossCountry services - are unable to enter the station.
Is the concourse still open?
The station building has been closed.
How long is it expected to continue?
Train companies are now estimating that the incident won't be resolved until 12pm.
Where are trains being diverted to?
Most trains are being sent to York instead, and rail replacement buses will transfer passengers to Leeds. Wakefield Westgate Station is also not being served during the disruption.
What do Network Rail say?
"Network Rail and British Transport Police have closed Leeds Station due to a vulnerable trespasser on the railway.
"The closure means that no trains are able to call at the station. It also means that the station building itself, including the concourses, are shut.
"Anyone who was planning on travelling to, from or through Leeds today is advised to delay their journey until later.
"Passengers can keep up to date with the latest travel information by checking National Rail Enquiries or checking with their train operator.
2Network Rail and British Transport Police would like to thank all those affected for their patience."