The Royal Adelaide Show has been cancelled for the second year in a row because of the ongoing COVID-19 pandemic.
Show organisers say the latest advice from SA Health would have capped daily attendance numbers at 10,000.
"This figure is not feasible therefore the 2021 Royal Show cannot proceed," they said in a statement.
Under normal circumstances, about 50,000 people attend the show each day with another 10,000 working or competing in various events.
The show had been scheduled to run for nine days from September 4 to 12.
Its cancellation follows similar decisions taken with the Royal Melbourne Show and Queensland's EKKA.
Premier Steven Marshall said the decision to cancel the show was taken with "huge regret".
"These mass events are extraordinarily difficult. I know there will be so many people who are disappointed," Mr Marshall said.
"The show society has looked at every single opportunity to work with SA Health to create a way that this could go ahead.
"But, unfortunately, this year it won't."
Mr Marshall said while crowd numbers were an issue, many of the rides and other attractions would not be allowed into SA from interstate under current border restrictions.
