Melbourne has edged out long-time front-runner Vancouver to be rated the world's most liveable city, a worldwide survey from the Economist Intelligence Unit said Tuesday.

The Australian metropolis topped the Global Liveability Survey's ranking of 140 cities worldwide, ahead of Canada's Vancouver which dominated the rankings for almost a decade but is now third behind the Austrian capital, Vienna.

Australian cities featured prominently in the top 10, with Sydney ranked sixth and Perth and Adelaide in joint eighth place, according to the survey, which is conducted twice a year.

Canada also did well, with Toronto and Calgary holding fourth and fifth places respectively. Helsinki in Finland (seventh) and New Zealand's Auckland (tenth) rounded out the top 10.

Cities were scored on political and social stability, crime rates, access to quality health care, cultural events, the environment, education and the standard of infrastructure.

"Australia, with a low population density and relatively low crime rates, continues to supply some of the world's most liveable cities," said survey editor Jon Copestake.

"Despite the rising cost of living, driven by the strong Australian dollar, these cities offer a range of factors to make them highly attractive."

Among other well-known cities, Paris came 16th, two places ahead of Tokyo. The top-ranked American city was Honolulu which came 26th, while London was a lowly 53rd, just behind Singapore.

Against the strong performance of Australian and Canadian cities, other parts of the world saw their rankings affected by austerity measures and unrest.

The Greek capital Athens dropped five places to 67th due to recent government cutbacks and protests.

The Arab uprisings prompted a fall in liveability for affected cities in the Middle East. This was most pronounced in Tripoli, where the descent into civil war saw its ranking plummet from 107th to 135th.

Zimbabwe's capital, Harare, was the least liveable city, just ahead of Dhaka in Bangladesh and the Papua New Guinea capital Port Moresby.