A source said: "They got on like a house on fire and he went away and discovered her music. He's a big fan."
Charles has now included the seven-time Brit award-winner's hit Love Me Again in a new playlist of 17 of his favourite songs to celebrate Commonwealth Day.
During the one-hour recording on Apple Music, called The King's Music Room, Charles pays tribute to Raye and speaks for the first time about meeting her.
Sitting at his desk at Buckingham Palace, he calls her "one of our most exciting and acclaimed contemporary singer-songwriters".
He adds: "Anyone who saw Raye perform at the Grammy awards will know that she is a great ambassador for British music."
The King also revealed he and Raye discussed her mother's Ghanaian heritage, which brought back fond memories for him of being given a bow and arrow as a boy at Balmoral by the then-Ghanaian Prime Minister, Kwame Nkrumah.
He recalled: "I went straight out and fired into a nearby pine tree and then couldn't get the arrow out again!"
Charles has included prolific Ghanaian star Daddy Lumba's track Mpempem Do Me in his playlist, which includes songs from 10 different decades.
His other choices include The Loco-Motion by Kylie Minogue and Diana Ross's ...