"Kate and I will always love and support one another and be the best of friends," he said in a statement. "No one knows me like Kate does, and we'll forever be appreciative of our mutual respect. We've both grown enormously through our relationship, but sadly, the time has come to part ways."
Guy also referenced the break-up in a tweet: "Rumours r true I'm afraid - Kate and I parted ways back in Jan. Sorry 2 be boring but we couldn't be closer. We'll love each other 4 ever."
Although the pair married in 1997, they'd actually first met years earlier, in 1980, when they attended the same college near Melbourne.
2015 has seen many celebrity couples calling it quits. Click through for a closer look at this year’s high-profile break-ups...