The actor/singer is said to be "devastated" after Blossom Murray, 88, passed away at a care home in Queensland, Australia.
She had been battling a long-term chest complaint and the couple moved Down Under from the U.K. three years ago in the hope the warmer climate would help her beat the illness.
According to Britain's Daily Mail, friends of the couple have jetted to Australia to comfort the 88-year-old star.
Bygraves was a popular singer and movie star in Britain in the 1950s and 1960s, and was once invited by Judy Garland to perform with her in New York. He later moved into light entertainment and TV work before retiring from showbiz.