RAILWAY STATION BLAZE: What we knowVideo of the blaze, which broke out in the main concourse of the station, was posted to social media showing smoke billowing from a building in the early hours.
The scene was evacuated and no casualties were reported, a spokeswoman for East Midlands Ambulance Service said.
Nottinghamshire Fire and Rescue Service tweeted: "There is a fully developed fire in the main concourse of the station - which has spread to the roof.
"Crews are currently working to stop the fire from spreading, thank you for your patience whilst we work to keep you safe!
"There are now 10 fire engines in attendance approximately 50 firefighters fighting the fire at the #NottinghamTrainStation".
The incident has caused delays across the local transport network.
Trains will not be stopping at the station "until further notice" and East Midlands Trains expect disruption to services throughout Friday.
Police said surrounding roads are closed and warned that buses and trams are also affected.
The force tweeted: "Station Street, Carrington Street and Queen's Road have been closed. Transport in the area will be severely disrupted."
A spokeswoman for East Midlands Ambulance Service said it is aware of the incident.
"We have a clinical manager and specialist paramedics at the scene," she said.
East Midlands Trains tweeted: "Please do not travel to Nottingham station this morning as trains will be unable to run and we are unable to provide road support to/from the station."
Travel disruption information posted on the East Midlands Trains website said: "At present we do not have a firm estimate as to when the station will be able to re-open; however, we expect trains to be disrupted on all routes through Nottingham for the whole of Friday 12th January."
An East Midlands Trains spokesman said: "Emergency services have been called to Nottingham station to deal with a fire. The station has been evacuated and there have been no reports of any injuries to customers or staff.
"We will continue to assist the emergency services in any way that we can.
"No trains will be stopping at the station until further notice.
"Our current advice to customers is not to travel to or from Nottingham station this morning.
"Passengers are advised to check www.eastmidlandstrains.co.uk for the latest travel information."