The BBCNo flights are able to take off or land at Edinburgh Airport due to an IT issue affecting air traffic control.
Engineers are currently working to resolve the issue while several incoming flights have been diverted, an airport spokesman said.
Passengers are advised to check the status of their flights with individual airlines before arriving at the airport.
More updates are expected later.
Flights have been canceled or diverted for several hours, including the following flights which will land at Glasgow Airport.
- Loganair flight LM316 from Exeter
- EasyJet flight EZY601 from Luton
- Ryanair flight FR6643 from Bratislava
- British Airways flight BA1462 from London
- EasyJet flight EZY3264 from Munich
- Ryanair flight RK860 from Agadir
- Ryanair flight FR2885 from Konas
The 15:30 Turkish Airlines flight from Istanbul and the 16:05 Ryanair flight from Gran Canaria have been diverted to Manchester Airport.
BBC News apprentice journalist Andrea Reskova is among those affected by the cancellation.
The 26-year-old traveled from Shetland to Edinburgh to get to her home in Slovakia for a vital blood test she had been waiting months for.
Reporting from the scene, he said: “I was made aware of the whole affair by Ryanair staff at the gate after being asked to queue for boarding.
“We were told to sit down because the flight wouldn’t leave for at least another 30 minutes, but it was already an hour ago.”
Andrea is now waiting for news and hopes her flight hasn’t been completely canceled – although heard some flights will be “indefinitely delayed”.
He said: “People around me are very frustrated, some of them have connecting flights to catch, so the general mood here is very tense.
“The airport staff are trying to calm everyone down. They have been very helpful, but I understand that some passengers are very worried.”