In the photo, a young Debbie in a stunning white veil and dress is seen cutting their wedding cake, while Donny, in a classic blue tuxedo, looks on with love.
They reminisced about their unforgettable honeymoon in Las Vegas back in 1978 and hinted at a more private getaway they might be taking this week.
Fans quickly took to social media to congratulate Donny and Debbie, sending their best wishes for many more years of joy together.