The Queen attended the Royal Windsor Horse Show to see her animals take to the parade ring, the first time she has been seen in public since March.
The 96-year-old man was driven to the fairgrounds in a Range Rover.
After missing the State Opening of Parliament, there was speculation that she would not be attending the annual event, which is one of the highlights of her year.
She sat in the front passenger seat of the vehicle, dressed casually in a white blouse and blue cardigan-style blouse and wearing sunglasses.
As the Range Rover pulled up near the parade ground, the Queen spoke to a small group, believed to be show officials, through the car’s open window.
She seemed relaxed, smiling and laughing as she chatted, while a few feet away dozens of photographers tried to capture the moment.
Inside the parade ring, the horses were put through their paces while classical music played on the public address system.
Dozens of members of the public were also eager to have a souvenir of the occasion, holding up camera phones to record their vision of the Queen.
The monarch was last seen in public when she attended a service marking the life of her late husband, the Duke of Edinburgh, in March with royals and a congregation of hundreds.
He reached his Platinum Jubilee in February, overcame a bout of covid after testing positive that month and celebrated his 96th birthday on April 21 in private at his Sandringham estate.
Last October, he spent a night in the hospital and for the next three months was under doctors’ orders to do only light duty, missing several high-profile events.
The Queen has been using a cane in public since she attended a service to mark the centenary of the Royal British Legion last October.