The 95-year-old said she had received many messages of good wishes, and that she and the royal family were “deeply touched” by the “support and kindness” from around the wrold.
"My family and I would like to thank you all for the support and kindness shown to us in recent days," she said.
She went on to say they continue to be reminded that Philip had "such an extraordinary impact on countless people" throughout his life.
Buckingham Palace also shared a photo of the Queen in happier times for her birthday, and along with the photo was the caption: “Today is The Queen’s 95th birthday."
“The Queen was born at 2.40am on 21 April 1926 at 17 Bruton Street in Mayfair, London. She was the first child of The Duke and Duchess of York, who later became King George VI and Queen Elizabeth.
“This year Her Majesty remains at Windsor Castle, during a period of Royal Mourning following the death of The Duke of Edinburgh," the caption read.
With her birthday falling within the two-week period of royal mourning for her late husband, commemorations this year are subdued.
According to the Ministry of Defence, traditional gun salutes in Hyde Park and at the Tower of London have been cancelled.
It is expected the Queen will spend her birthday with some family members and staff at Windsor Castle, after she laid her husband Philip to rest on Saturday.
She led mourners in the small, heartfelt ceremony remembering the Duke of Edinburgh, and paid tribute to her husband with special touches to her outfit.
She wore the traditional colour of mourning, an all-black ensemble, nut she also donned Queen Mary's Richmond Brooch, according to Express.
The diamond pin is highly sentimental for Her Majesty as she inherited the piece from her grandmother and wore it during her and Philip's honeymoon and on their 73rd anniversary.