Gary revealed to his fans on Twitter: "17 years ago today we tied the knot! Happy anniversary Mrs.B xxxx." He followed up the post with an idyllic snap of the couple embracing and looking out to sea.
"Happy Anniversary to the most beautiful couple in show business," replied one fan to the tweet that pulled in more than 5,000 likes. "So nice to see you both so happy. Have a lovely day together."
"Aww have a lovely love filled day! She's a lucky lady but then you're also a lucky man," wrote another.
Gary and Dawn met when Dawn was a dancer on the band's tour
Gary rarely shares photos of his wife Dawn, who he met in 1995 when she was a dancer on the band's Nobody Else tour. However, he was unable to resist sharing a photo from a night out in New York, and explained two years ago: "Dawn will kill me for posting this but I'm so proud of her tonight."
The couple married in 2000 and have three children – Daniel, Emily and Daisy. In 2012 the proud parents sadly lost their fourth child, a daughter named Poppy who was delivered stillborn.
The couple married in 2000
Gary is focusing his energy and time on his new BBC One show, Let It Shine. The Saturday night show will be looking for five young men to star in a new stage musical based on the music of the massively popular boyband.
The other current members of Take That – Mark Owen and Howard Donald – are involved too.
"We're all excited," Gary told HELLO! magazine. "We're all producers of the show. This is our baby, really. It's a celebration of our career. Hopefully this music will live on way beyond our capability to perform. When we're in wheelchairs being pushed around an old folks' home, this musical will still be touring."