The Rally Wales GB, scheduled for October 29 to November 1, was cancelled for the first time in more than 50 years due to uncertainties surrounding travel and mass gatherings amid the Covid-19 pandemic, organisers of the race said on Tuesday.
The event, first run in 1932 and among the United Kingdom's top motor sports races, had previously been stopped by World War Two in 1940, the Suez Crisis and resultant petrol rationing in 1957 and the foot-and-mouth disease outbreak in 1967.
It was the fifth round of the 13 race FIA world championship to be cancelled following Rally New Zealand last week, as the novel coronavirus outbreak continued to wreak havoc on the schedule this season.
"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," Motorsport UK chairman David Richards said in a statement.
Rally GB, which has been set in Wales since 2000, is one of two rounds that have been permanent fixtures in the annual world championship since the series was inaugurated in 1973.
"In recent years, the huge appeal of the latest generation of World Rally Cars plus the presence of local star Elfyn Evans - a winner in 2017 - have drawn record crowds to the wonderful Welsh forests," Richards added.
"But this isn't the appropriate time for us to be planning for and promoting an event that brings tens of thousands of visitors, many from outside the country, into rural Welsh communities.
"... We'll instead start focusing our attentions on creating an even bigger and better world-class showcase for 2021."
More than 40 500 people have died in the UK due to the flu-like virus.