Prince William, Kate and baby George have arrived in Sydney to kick off their tour of Australia.

The Duke and Duchess of Cambridge have left behind dreary New Zealand for sunny Sydney, with Kate dressed to match.

Prince William, Kate and baby George emerged onto the tarmac at Sydney Airport on Wednesday afternoon to be greeted by sunshine, a bit of wind and the governor-general, prime minister, the NSW governor, and the waiting media.

Kate, who favoured jewelled-coloured coats in New Zealand, wore a short-sleeved, form-fitting, buttercup yellow dress by Serbian-born, London-based designer Roksanda Ilinic as she carried George down from the RAAF plane.

William opted for a classic navy suit.

Little George – in a spotless white romper suit, with smocking on the front – was again a star, seemingly trying to shake hands with the governor-general’s wife.

The eight-month-old perked up a little after he was handed off to his father but took little interest in the gathered dignitaries.

Governor-General Sir Peter Cosgrove and wife Lynne, NSW Governor Marie Bashir and her husband Sir Nicholas Shehadie, and Prime Minister Tony Abbott and wife Margie, welcomed the royal family to Australia.

But outgoing NSW Premier Barry O’Farrell, who had been slated to part of the welcome party until his shock resignation on Wednesday morning, was absent from the tarmac.

Twenty-two-year-old Joscelyn Sweeney from the NSW beach town of Vincentia had the honour of presenting the duchess with a posy of vibrant native flowers.

She told reporters she had been looking forward to the royal encounter “forever and ever”, after her mother wrote to tell the duke and duchess they had become role models for the young woman, who has Down’s syndrome.

But there were no nerves before Ms Sweeney’s chat with the duchess, she said.

“She’s so nice,” she said.

“And I brought a book for Prince George to read.”

But others missed out.

Mum Leanne brought a brood of children and a bunch of tulips but was forced to watch on from behind a heavy security contingent.

“We were going to throw them over the barbed wire but we didn’t get there,” she joked.

After the informal welcome, the royal couple headed straight for the Opera House for a civic reception. Thousands waited on the forecourt to cheer wildly as the couple arrived.

Both Kate and William waved to the crowd, but weren’t able to meet and greet with the throng.

Monica, 54, said Kate looked “beautiful inside and out”.

“I’m here to see Kate. I don’t care much about William. I wanted to see if she looks as good in real life as she does in the magazines,” the St Ives resident told AAP.

Before stepping inside, Kate and William took in some of the stunning sights of Sydney Harbour on a gorgeous, sunny autumn afternoon.

Inside, William made a short speech praising Australia.

They were then scheduled to be taken by police boat to Admiralty House where they will be hosted by Sir Peter.

The royals spent the past 10 days in New Zealand where, despite rainy, cold weather for all but two days, they charmed the New Zealanders.

In Australia, they’ll visit the Blue Mountains, Taronga Zoo, Amberley RAAF base, Brisbane, Manly Beach, Uluru, Adelaide and Canberra.

They’ll end their visit by attending Anzac Day services in Canberra on Friday week.