Harry, now fifth in line to the throne, issued a statement Monday, remembering the monarch he knew as "granny."
"Granny, while this final parting brings us great sadness, I am forever grateful for all of our first meetings—from my earliest childhood memories with you, to meeting you for the first time as my Commander-in-Chief, to the first moment you met my darling wife and hugged your beloved great-grandchildren," he wrote. "I cherish these times shared with you, and the many other special moments in between."
Harry also remembered his grandmother, Britain's longest-reigning monarch, for her "commitment to service and duty," writing, "She was globally admired and respected. Her unwavering grace and dignity remained true throughout her life and now her everlasting legacy."
He ended his statement on a more personal note, thanking the queen for her "sound advice" and for her "infectious smile" and writing that he is glad his grandmother is now reunited with her beloved husband of 73 years, Prince Philip, who died last year at the age of 99.
"We, too, smile knowing that you and grandpa are reunited now, and both together in peace," Harry wrote.
Harry and his wife Meghan, the Duchess of Sussex, who live in California with their two children, were in the U.K. last week for several charity events when the queen died at Balmoral Castle, her Scotland estate.
After rushing to be with members of the royal family in Balmoral, Harry returned to Windsor last week, where he and Meghan have been staying in their Frogmore Cottage home.
On Saturday, Harry and Meghan made a surprise appearance with Harry's older brother, Prince William and his wife Kate, the Princess of Wales, to view tributes to the queen outside Windsor Castle and speak with people who gathered there to mourn.
The appearance marked the first time the two couples had been seen together in public since 2020, when Harry and Meghan attended their final royal engagement before stepping down as senior working royals.
The two couples attended the National Service of Thanksgiving in June for the queen's Platinum Jubilee, celebrating her 70 years on the throne, but were not seen publicly interacting with each other.
Amid reports of tension between Harry and William, the heir to the throne, their joint appearance with their wives at Windsor Castle was seen as a sign of unity for a grandmother both men have spoken highly of over the years.
Harry and Meghan named their daughter Lilibet "Lili" Diana Mountbatten-Windsor after the queen, whose family nickname was Lilibet. Her middle name, Diana, is a tribute to Harry's mother, the late Princess Diana.
Lili joined her parents and her older brother Archie, 3, in London for the queen's Platinum Jubilee, where she celebrated her first birthday and is believed to have had her first meeting with the queen.
Even after leaving his royal role, Harry continued to speak fondly of the queen.
"My grandmother and I have a really good relationship and an understanding, and I have a deep respect for her," Harry said in an interview with Oprah Winfrey last year.
Harry also told Winfrey the queen has been "amazing throughout" his relationship with Meghan, a sentiment echoed by Meghan, who said the queen was one of the first family members she met in her relationship with Harry.
"The queen, for example, has always been wonderful to me," the duchess said. "I mean, we had one of our first joint engagements together. She asked me to join her."
"I just really loved being in her company," said Meghan, who added that the queen gave her pearl earrings and a matching necklace for their June 2018 joint engagement. "And I remember we were in the car ... going between engagements, and she has a blanket that sits across her knees for warmth, and it was chilly and she was like, 'Meghan, come on,' and put it over my knees as well."
"It made me think of my grandmother, where she's always been warm and inviting and really welcoming," Meghan said.