The Queen will resume her official public engagements next week following a bout of gastroenteritis, Buckingham Palace has said.
She will attend the annual Westminster Abbey service marking Commonwealth Day on Monday, accompanied by the Duke of Edinburgh.
A Palace spokesman said it was "business as usual" for the Queen, who suspended her engagements this week, including a trip to Rome, following the illness.
The Queen, 86, was struck down last Friday by the stomach bug, which commonly causes symptoms of vomiting and repeated episodes of diarrhoea.
She stayed overnight on Sunday at the private King Edward VII's Hospital in central London, being assessed by doctors, and was discharged on Monday.
Concerns were raised about the Queen's general well-being as it was the first time she had been admitted to hospital in almost 10 years.
But she left the hospital looking well and cheerful.
During Monday's service entrepreneur Sir Richard Branson will give a speech and there will be performances by soul singer Beverley Knight and indie-rock favourites The Noisettes.
The Queen's other engagements include a visit to Tech City in London's East End to tour a number of companies next Wednesday.
The following day the monarch will attend a service at the Guards' Chapel in central London to commemorate the 175th anniversary of the Soldiers and Airmen's Scripture Readers Association.