Cambridge Folk Festival in England is now in its 50th year and organisers were desperate to secure a top billing from the Belfast singer after being rejected several times in the past by the Brown Eyed Girl hitmaker.
Eddie Barcan, who runs the festival, tells Reuters: "I've tried (to book Morrison) many times in the past. You just keep chipping away."
Morrison will close the festival on Sunday.
The event will also feature performances from Roseanne Cash and Sinead O'Connor.