The Duchess of Cambridge will be the Queen's representative at the celebrations to commemorate the 50th anniversary of Malta's Independence.
Kate Middleton will be in Malta on September 20 and 21.
The Sunday Times of Malta had revealed earlier this month that the duchess was expected to be the guest of honour during Malta's Golden Jubilee celebrations. The British High Commission at the time had said no decision had yet been taken.
This will be the duchess's first overseas official visit without Prince William.
The Queen last visited Malta in 2007.
Following the announcement the official British Monarchy account tweeted:
"The Queen and the Duke of Edinburgh lived in Malta when they were just married, while the duke was on naval service."