The Royal Pavilion & Museums Trust said the closure until July 6 was to allow for a filming project at the venue.
Brighton Museum and Art Gallery will open on Monday, June 28, instead of the usual closed day to give visitors a chance to enjoy some fascinating art and culture instead, the trust said.
A spokesman said: "All guests who have made an advance booking have been contacted and will be offered alternative dates or a refund. We apologise for any inconvenience caused."
The Royal Pavilion will reopen on Tuesday, July 6, at 9.30am.
For more information on booking a ticket, visit https://brightonmuseums.org.uk/royalpavilion/visiting/Don't forget to buy your copy of the Brighton Indy, which includes a weekly local nostalgia feature provided by the Royal Pavilion and Museums Trust.