The Queen is to visit Norwood's Ravenswood village for people with learning disabilities next month.
Norwood president Richard Desmond told the charity's annual dinner at Grosvenor House on Monday that The Queen would tour the Berkshire facility on December 11.
"Something that sets Norwood apart is that we have the Queen as our royal patron," he said. "I am delighted that she has requested to meet children and adults who use our services, together with staff who support them.
"We are all looking forward to showing her our fantastic services. Whilst she is at Ravenswood she will be opening the new Pamela Barnett Centre for adults with profound and multiple disabilities."
Norwood has enjoyed royal patronage since 1815. The Queen previously attended a Norwood event in 1985 and other royal visitors have included Princess Diana and Princess Alexandra.
In another key dinner announcement, chairman designate Bernie Myers revealed plans for an employment opportunities centre, providing support and training for adults with learning disabilities to prepare them for the employment market.
The dinner raised £3 million, prompting Mr Desmond to applaud "the generosity of Norwood's donors who have demonstrated that even in this tough financial climate, they are there for the children, families
and adults who rely on Norwood's support".