Australia now has more of them than Brazil or Spain. John Collett looks at the reasons why.
Thanks to the resources boom, the ranks of Australia's millionaires swelled more quickly last year than in most other developed countries.
The number of Australians with financial assets of at least $US1 million ($1.03 million), excluding the family home but including superannuation, rose 7.1 per cent to 172,000, according to a survey by Merrill Lynch and Capgemini.
Of the 71 countries surveyed, Australia ranked 10th by number of millionaires.
Australia has more millionaires than Brazil and Spain, despite those countries having much bigger populations. As expected, the US is still the richest country and is home to 3 million of the world's 10 million millionaires.
Yet the large emerging economies of China, India, Russia and Brazil are growing their ranks of millionaires much more quickly than countries with fully developed economies. China, which had 415,000 millionaires last year, is on the verge of overtaking Britain and its 495,000 millionaires.
However, the credit crunch and turmoil in world financial markets slowed the millionaire club's growth rate last year and is expected to affect this year as well.
Wealth in Australia has been generated in several ways, says Thomas Alexy, Merrill Lynch's head of global wealth in Australia. Certainly, the booming demand for commodities has helped, he says.
"But the wealth comes in a lot of shapes and forms."
Apart from the handful of lottery winners, the prerequisite for building wealth is either being successfully self-employed, having a job with a high income or receiving an inheritance.
Yet plenty squander their income without having much to show for it.
Those with discipline who get good advice and take full advantage of Australia's quite generous tax system for borrowing to invest tend to do the best, Alexy says.
He says successful long-term investors are those who preserve their capital with good asset allocation and "never try to hit the big home run".
Andrew Inwood, the founder of brandmanagement, which conducts market research for the financial services industry, estimates that one in four of Australia's millionaires was born overseas.
"Migrants with money used to be mostly from Europe but are now from Asia and even the Middle East and Africa," Inwood says.
He says another striking feature of Australia's millionaires is that about three-quarters own their own small or medium-sized businesses and more than 70 per cent are tertiary educated.
Doug Turek, the founder of high-end financial planning firm Professional Wealth, says wealth is driven by age, income and a few habits or traits - the main one being patience.
"Barring a few dotcom or iron ore millionaires, it is very hard to accumulate assets quickly; you need time for these things to build. It doesn't necessarily matter if your investment focus is strictly shares or direct property, or a mix of those things or even building a business. The key is having a disciplined focus over a long period of time."
Turek has developed an online survey (www.wealthbenchmarkets.com.au) where people enter their financial details anonymously and in return are told how their wealth compares with others of the same age and income.
More than 90 per cent of the participants in the survey are male. "Males seem to be picking up higher income roles than females," Turek says.
"There is plenty of other research to show that women, because of their time out of the workforce and inequalities in roles and promotion, are not as wealthy as men."
However, Turek says the marked predominance of wealthy males in his online survey may be partly because men are more comfortable than females in sharing their financial information, even though it is given anonymously.
"It is a male-dominated wealthy world," he says.
One of the key determinants of wealth is the family situation. "Being together and not divorced is a very strong success indicator because of the tremendous financial costs of separation over a lifetime," Turek says. "If you have been divorced, your net worth will only grow to three-quarters of those who are not."
Inwood, whose company recently conducted a focus group with wealthy people, says some millionaires enjoy an extravagant lifestyle but most are modest in their spending. They tend not to spend that much on clothes and holidays, and are generally "tight" with money but will spend on quality things.
Turek says working overseas is also good for building wealth. "We have found that those that have spent time working overseas have a higher net worth than those who have not.
"You can think of professionals who have worked for a law firm in London or for an investment bank. Then there are those who have grown up in another culture and economy, and have come to Australia as a wealthy migrant."
It is not only those on particularly high incomes that have become wealthy.
Inwood uses a lower threshold for the definition of a high-net-worth individual than many other researchers. His definition is those with assets of more than $450,000 outside of their homes and superannuation. Recent research by brandmanagement shows that about half of them earn less than $100,000 a year.
They are those in their 50s and 60s, the baby boomer generation who have enjoyed rising house prices during the 1990s and 2000s and have good savings and investment habits. Home ownership has given them a springboard to borrow and invest.
Now that house prices are much higher than when the baby boomers first got onto the property ladder, it remains to be seen whether younger generations will fare as well.