Katherine Jenkins performing at Cardiff's Millennium Stadium
Soprano Katherine Jenkins will become the first person to sing the Welsh national anthem, Hen Wlad Fy Nhadau, at an FA Cup final on 17 May.
The former teacher from Neath will perform before the Cardiff City v Portsmouth showdown at Wembley Stadium.
She had been asked to accompany fellow soprano Lesley Garrett in a rendition of God Save the Queen.
But she asked authorities to let her sing the Welsh national anthem with the Coldstream Guards Band instead.
"It's a fantastic honour for me to sing our national anthem anywhere in the world, but to sing at a FA Cup Final at Wembley is going to be something really special," she said.
She said she would be supporting the Bluebirds.
"Who will I support? Who will all right-minded and passionate Welsh sports fans across our country support that day?"
The last time Cardiff reached the FA Cup final in 1927, the English version of the Welsh anthem - Land Of My Fathers - was sung.
The FA estimates between 480 million and 500 million people will watch the cup final worldwide.
Jenkins has regularly appeared before rugby internationals to sing the Welsh national anthem.