"They are no longer a couple," Bublé's rep Liz Rosenberg confirms to PEOPLE.
The Golden Globe-winning British actress, 25, and the 32-year-old crooner met in 2005, when she popped backstage to say hello to him after one of his concerts.
Each was the other's biggest cheerleader. "I get tears in my eyes when I see him onstage. It's overwhelming," Blunt told PEOPLE last year.
The feeling was mutual for Bublé. "Every time I see her onscreen, I fall in love with her all over again," he said.
After Bublé, Blunt's second biggest fan was her boyfriend's mom. "I love her," Amber Bublé, 53, gushed to PEOPLE this spring. "In fact if he doesn't marry her, I'll kill him. But we'd find someone in the family to marry her because we're not letting her go, ever. She's just the best thing ever and they're perfect together."
But the strains of a long distance relationship may have weighed on the couple, who shared a home in Vancouver. With their busy acting and touring schedules, "It's not easy," Bublé told PEOPLE in April.
The split was first reported on perezhilton.com.