Riddlesworth Hall School near Diss, Norfolk, closed in April this year after more than 75 years due to “unprecedented financial challenges”.
The independent day and boarding school for children aged between two and 13 was attended by Princess Diana in the 1970s.
The 27-acre site includes the Grade II listed Georgian hall built in 1792 and 10,232 sq. ft of converted stables and coach houses.
Richard Shuldham, associate in the development team at Savills Norwich, said: “Unfortunately the school was forced to close its doors earlier this year and the decision has now been taken to put the site on the market.
“The sale represents an exciting opportunity for any new owners to shape the future of a landmark building.
“The private setting of the hall and grounds lends itself to a variety of uses.
“We expect the site to be of interest to the education, hotel, leisure and healthcare sectors, as well as the residential sector.”
A spokesman for the school said in April that they were all “extremely saddened” by the decision to close but it was “decided by the owner that the school was no longer viable”.
He added: “The school has been facing unprecedented financial challenges for several years now which is due, in part, to the impact of the pandemic and the current economic climate.”