The former Wimbledon tennis champion and the 26-year-old beauty have been an item for more than nine years and their representatives have confirmed the engagement.
The couple first met at the US Open in New York in 2005 and Andy, 27, has credited much of his recent success to her unwavering support, especially after he lost the 2012 Wimbledon Final in heartbreaking fashion to Roger Federer.
Andy was preparing to appear in the International Premier Tennis League in Asia when the news was announced and he's given no indication of the news to his Twitter followers, instead writing: ''Off to the Philippines for the first time today, should be a fun trip... Anyone got some suggestions for first time tourists in Manila? (sic)''
Andy is notoriously coy when talking about his relationship to the media and he caused a storm in January when he joked about plans to marry Kim during a Twitter Q&A with fans.
He tweeted: ''We're getting married just after Wimbledon, should be a great day.''
However, he later clarified his statement, explaining that it was just a joke.
His new album Underneath It All is out now.