Wealth in Asia

Millionaires are picking Singapore over Hong Kong

See which country millionaires are choosing

Hong Kong's social unrest may be prompting globe-trotting millionaires to locate to Singapore instead, according to a wealth-tracking report out on Tuesday.

The two cities are locked in a struggle for supremacy as Asia-Pacific financial hubs, attracting financial professionals and investors away from London and New York.

"Though Hong Kong has a much higher millionaire population than Singapore (193,000 against Singapore's 154,000), recent events such as the Umbrella Revolution may have turned migratory high-net-worth individuals (HNWIs) away from the city," Oliver Williams, head of WealthInsight, said in a report from the research company.

Approximately 1 in 35 Singaporeans are currently millionaires, according to WealthInsight. The city-state's HNWI population is seen growing by 18.3 percent to reach 188,000 by 2020, making around 1 in 30 Singaporeans millionaires.

By comparison, the number of millionaires in Hong Kong is seen growing by 15.6 percent over the next five years.

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In both cities, the majority of HNWIs are residents rather than expats, but the growth in their numbers over the next five years is seen being driven largely by expatriates, according to WealthInsight.

"Singapore's burgeoning financial markets, renowned private banking and superior quality of life are continuing to attract HNWIs from neighboring countries. We're currently seeing a large influx of Indian and Chinese millionaires into the country," Williams said.

In recent months, U.K. emerging market-focused banks have touted the idea of relocating to Asia — Hong Kong in the case of HSBC and Singapore for Standard Chartered.

Well-known HNWIs who have relocated to the region include U.S. veteran investor Jim Rogers, who lives with his wife and two daughters in Singapore.

Read MoreHere's why Jim Rogers mulls ditching his US citizenship

— By CNBC's Katy Barnato. Follow her on Twitter @KatyBarnato.