Camilla cut the ribbon to open the racecourse’s new Bustardthorpe Development before walking through the stand and speaking with racegoers and officials.
Dressed in pale blue, the Queen met members of the Falcons Display Team and watched the action with racing manager John Warren on Saturday.
After the first race, she made her way to the pre-parade ring to see her horse, Reaching High, parade ahead of the Sky Bet Melrose Stakes in which he was unplaced.
Following that, she crossed over the track to meet Kevin and Pam Atkinson, founders of the charity New Beginnings, who retrain ex-racehorses for new careers – for example, in dressage.
There she met Goldream, the equine ambassador to the racecourse, and another horse called Nearly Caught, spending time stroking them both.
Ms Atkinson said: “We were delighted to meet the Queen and introduce her to Remy (Goldream) and Nearly Caught (Nico).
“We’ve been working with York Racecourse for 14 years so for the Queen to come and acknowledge our work was fantastic, she seemed very keen to stroke Remy!”