A computer outage has been blamed by the company for the chaos which they say has “impacted flights”. The firm operates out of Heathrow, Manchester and Edinburgh airports.
On Monday morning flights across the world were affected by what the company said on Twitter was a “major system-wide network outage”.
A spokeswoman for Delta said: “Delta experienced a computer outage that has impacted flights scheduled for this morning.
“Flights awaiting departure are currently delayed. Flights en route are operating normally.
“Delta is advising travellers to check the status of their flights this morning while the issue is being addressed.”
The airline began in 1924 as an aerial crop dusting operation called Huff Daland Dusters, and now serves more than 160 million travellers, according to its website.