The Wales-based event, which was due to host the penultimate round of the 2020 season on October 29-November 1, joins Portugal, Kenya, Finland and New Zealand on the list of rounds cancelled in the wake of the global coronavirus pandmemic.
With Rally Chile having also been called off before the COVID-19 crisis began, it leaves just five more rallies that could potentially still take place later this year, including two events that have already been postponed from their original dates.
Turkey, Germany and Japan are the only rallies that are still scheduled to be held on their original dates, while Argentina and Italy have not yet been rescheduled.
“This is not a decision that we have taken lightly but, in close consultation with our chief funding partner the Welsh Government, it is sadly one we are obliged to make in light of the ongoing global coronavirus pandemic,” said Motorsport UK chairman David Richards.
“As the governing body of UK motorsport, our overriding responsibility and absolute priority is always the safety of all involved whether they be competitors, officials, spectators or the many thousands of volunteers who share our passion for this sport, and we thank them all for their ongoing support and enthusiasm in these difficult times.
"While significant progress is being made to combat the virus, there remains considerable uncertainty regarding mass gatherings, social distancing and travel restrictions, plus the possibility of a resurgence of viral transmission later in the year.
“We have been closely monitoring the guidance issued by Government and it is becoming increasingly clear that it is impossible to make plans with any certainty for such major events in the autumn.
"We therefore have to accept, with an incredibly heavy heart, that cancelling this year’s event is the only responsible and prudent option. We will instead start focusing our attentions on creating an even bigger and better world-class showcase for 2021.”
Rally GB had been a fixture on the WRC calendar since the championship's inception in 1973. The last time the event wasn't run at all was in 1967.
British Championship cancelled entirely
The news of Rally GB's cancellation was swiftly followed by the announcement that the 2020 British Rally Championship will not take place at all this year.
Only one rally, the Cambrian Rally in February, has taken place so far this year, and three of the remaining five events on the calendar had already been called off. Rally GB was added as a reserve event to the calendar before its cancellation.