The Princess of Wales looked holiday-ready as she arrived at Westminster Abbey for the festive event.
Kate donned head-to-toe winter-white paired with a long white coat over a white top and trousers.
The Princess of Wales completed the look with a coordinating Strathberry handbag, heels, and her dangling Van Cleef and Arpels earrings.
Princess Kate's monochrome white look caught everyone's attention at the concert.
Princess Kate was accompanied by her husband, Prince Williams, and kids, all dressed to kick off the holidays in style.
Princess Kate lit up the candle with Princess Charlotte and Prince Louis.
"Join me this Christmas Eve for a special carol service as we say a heartfelt thank you to all those supporting the very youngest members of our society during those crucial early years,” Princess Kate said in the message.