"We deeply regret the loss of life of a participant," they said in a statement on Facebook.
No further details have been released about the individual but the Great Run Company said its priority was to ensure next of kin had been informed.
About 57,000 people took part in the event which is run over 13.1 miles and is in its 35th year.
The event began in Newcastle with the finish line 13.1 miles away in South Shields.
Mo Farah won the men's elite race - his second consecutive win in the half-marathon.
Kenyan Mary Keitany won the women's race and David Weir achieved a record-equalling sixth win in the elite wheelchair competition.
In its full statement on the death of the runner, organisers said: "We deeply regret the loss of life of a participant at the Great North Run today and offer our deepest sympathy and condolences to the family and friends of the individual concerned.
"In such circumstances there is a strictly planned procedure we adhere to. Our priority is to ensure that the next of kin are informed and therefore we will not be in a position to make any further comment today."
A runner taking part in the Great North Run has died, the race organisers have said.