The couple, who got engaged in September just three months after they started dating, looked adorable as they posed for photographers on the red carpet.
She recently told "Entertainment Tonight," "From day one I just knew immediately and it's been magic. We have all the same family friends. We grew up with the same people, we just never met. So I kind of feel that I've known him my whole life."
Several other stars attended the polo match, including model Alessandra Ambrosio who stunned in a pink polka dot dress and had her two children in tow, and Mandy Moore, who wore a black slip dress and a pink jacket.
Check out more photos from the event...