While it might have been George's first appearance, eagle-eyed royal-watchers will have noticed that it's not the first time we've seen his blue romper suit.
Kensington Palace confirmed that the same cute suit was worn by his father for the Queen's official birthday parade back in 1984.
Of course, the accolade of coolest royal still goes to Prince Harry, who made a much bolder statement during an early balcony appearance.