Despite the slowing economy, the number of ultra-wealthy Australians is expected to continue growing in the next five years, boosting the demand for luxury real estate, according to the latest report from Knight Frank.

By 2023, around 613 will join the group of ultra-high-net-worth individuals (UNHWIs), whose individual net worth exceeds $44.8m.

The growth in the ultra-rich population is expected to be driven not just by the healthy stock and bond markets but also by the robust long-term property price growth, said Knight Frank head of research Michelle Ciesielski.

In fact, over a third of the total wealth of Australia's super-rich comes from residential properties, with each owning three homes on average.

"The ultra-rich are not necessarily just looking for one home to live in, they tend to have the main family home, the city pad and country estate," Ciesielski said.

Sydney will remain the most desirable location for UNHWIs. The Knight Frank report said the city's prime residential price will likely rise by 2% by the end of this year and by another 3% next year.

Melbourne will continue to be the second-most favoured destination for the ultra-rich, followed by Perth.

Ciesielski said the prime residential market is poised to witness sustainable and robust growth even with global uncertainties that could potentially affect confidence.

"We think the prestige market still has further growth to be had. There remains a buoyancy in the local prime market indicators," Ciesielski said.