The 85-year-old monarch has been met with rapturous receptions in Canberra, Melbourne, Brisbane and Perth on her 10-day visit which some have speculated could be her last to the distant realm.
Addressing thousands of flag-waving wellwishers gathered in sunshine alongside the banks of Perth's Swan River, the queen said that she and Prince Philip had enjoyed their latest tour immensely.
"I can think of no more fitting way to end my visit... than in this idyllic Swan River setting which I have enjoyed on so many occasions," she said.
"Once again we will return to the United Kingdom with fond memories of our time here."
The queen, who last visited Australia in 2006 to open the Commonwealth Games in Melbourne, is a much respected figure Down Under despite frequent murmurings about the former colony breaking ties with Britain and becoming a republic.
Wearing a purple-tinted floral dress and short white coat and matching hat, the queen and Prince Philip mingled with Perth residents at an Australian barbecue as their final public engagement in Australia.
The royal couple are due to fly back to London later Saturday.
