Buckingham Palace said in a statement: “The Queen, having sprained her back, has decided this morning with great regret that she will not be able to attend today’s Remembrance Sunday service at the Cenotaph.
“Her Majesty is disappointed that she will miss the service.”
It’s only the sixth such service missed by the Queen in her 69-year-long reign.
She missed the event four times while on tour overseas and twice while pregnant.
A wreath was laid on the Queen’s behalf by Prince Charles.
It comes after the palace had said it was the Queen’s “firm intention” to attend the ceremony despite recent health issues.
The Queen had been advised to rest after spending a night in hospital on 20 October for “preliminary investigations”.
It was the 95-year-old’s first overnight hospital stay in eight years.