The decision, taken by the honorary show director Mark Spencer with his chief stewards, will see livestock classes completed a day early and public told not to visit the 168th Royal Show tomorrow because health and safety precautions are being implemented.
Spencer said that the unusually high rainfall since the show started on Sunday resulted in the normally sound showground and car parking areas becoming saturated.
"We consulted with our own health and safety officers, Warwickshire police and viewed Met Office forecasts to arrive at the decision," he added.
"We managed showground and car parking ground conditions before and during the first three days of the show, spreading large amounts of wood chips, chatter and straw. However, continuing heavy rain showers meant the ground could not take more water. We had no option other than to protect the safety of visitors, standholders and others involved in the event."
Spencer continued: "Clearly we are very disappointed to have made the decision to end the show a day early but are sure everyone will understand that safety is paramount.
"Our stewards are intent on running the equestrian competitions on the higher, and therefore drier, ground to ensure those competing in HOYS qualifying rounds are not disappointed."