Heavy rain had forced the cancellation of Friday's event but organisers announced shortly before 11.30am on Friday that the WHOLE event was now off.
A spokesperson said: "We are very sorry to announce that the Royal Lancashire Show has been cancelled. This follows health and safety assessments this morning and a review of the weather forecast for the coming weekend.
"The extremely heavy rain on Wednesday night/Thursday morning created very difficult conditions which deteriorated when vehicles arrived to set up yesterday. As a result the organisers took the decision to close the Show to the public but continue with the animal classes.
"In spite of an "army" of agricultural contractors who were brought in to repair the ground, the continuing rain has made this impossible. This, combined with the forecast of further heavy rain later today and tomorrow, has resulted in the cancellation.''
Gordon Roberts, Show Chairman, said, "We are obviously extremely upset and disappointed for the traders/exhibitors/ competitors and everyone who has worked so hard and supported the Show. The team are devastated that the weather has defeated us again this year."
He added: "Our priority now is to ensure that the Show Ground is closed and everyone can leave with the minimum disruption. If the anyone has any queries, we would ask them to contact us next week."