In the sexy selfie, Chatto poses shirtless, wearing a pair of Calvin Klein boxers while flexing his impeccable abs and biceps.
"#Chatnoleg," he captioned it.
Fans couldn't stop gushing over Chatto's physique in the comments section of his post, writing things like, "Would royally smash," "Woof," "Looking for an Australian princess?" and "Well now, sexy boy. I won't tell the queen!!!!"
Chatto is the son of Lady Sarah and Daniel Chatto. His grandmother is Queen Elizabeth II's sister, Princess Margaret, Countess of Snowdon.