The former Spice Girl turned fashion designer, 48, praised the late monarch as the “ultimate icon in every way and the epitome of elegance” in a post to her 30 million followers on Instagram.
Beckham, whose husband David queued for 13 hours to see the Queen lying in state this week, also shared a series of photos of the monarch in various outfits, with her corgis and horses.
A number of Beckham’s designs have been worn by royals in recent years, including the Duchess of Sussex and the Countess of Wessex.
In her post, Beckham wrote: “I’ve spent the last week reflecting on the loss of Her Majesty Queen Elizabeth II and how she was a powerful source of inspiration not just for me, but for so many around the world.
“The ultimate icon in every way and the epitome of elegance, she will live on in our hearts and minds forever.
“I offer my deepest sympathy and heartfelt condolences to the Royal Family at this time, and we join them in mourning the loss of our beloved Sovereign.”
She signed off her message with the initials VB.
Beckham was made an OBE in the 2017 New Year Honours for services to the fashion industry and received the honour from the new Prince of Wales during an investiture ceremony at Buckingham Palace.
On Friday, her husband David spoke to press after completing the five-mile public line to see the Queen lying in state at Westminster Hall, saying: “It is emotional for everybody involved. Her Majesty was someone special and will be missed just by everyone.”
David, who queued alone, was made an OBE for his services to football in the Queen’s birthday honours list in 2003 and also met her on several occasions.