The couple will exchange vows at the lavish Hampton Court Palace on Saturday (27Sep14), just five months after becoming engaged, according to DailyMail.co.uk.
A source tells the website, "Katherine and Andrew are tying the knot on Saturday at Hampton Court Palace. They've been coy about the details surrounding the wedding and were keen to keep it under wraps.
"The couple have relatives flying in from America, and everyone is excited to be part of their big day.They're a lovely couple and no doubt the wedding will be a wonderful day for all involved."
The marriage will be the blonde beauty's first. The 34 year old was previously engaged to British Tv presenter Gethin Jones in 2011.