"We are expecting William and Kate to attend the championships on 19 April for the $4million (£2.2million) Queen Elizabeth Stakes," a racing insider told the Daily Telegraph.
There is one horse that Kate and William will be cheering in particular – the Queen’s racehorse Carlton House, which has recently been trained in Australia, is due to take part.
The Duke and Duchess of Cambridge’s tour itinerary has yet to be officially confirmed, but it is "anticipated" that they will take Prince George with them when they visit both New Zealand and Australia in April.
"Clearly it is hoped and planned that Prince George will accompany them but being new parents and the trip being several months away yet, a final decision will be made nearer the time," said a source.
Prince William was a baby when his parents Prince Charles and Diana, Princess of Wales, visited Australian in 1983 for a six-week tour. William was the first royal baby to accompany his parents on a royal tour.