Auf Deutsch fast besser zu umschreiben, aber Singapurer ist richtig,
falls er sich unter die Singalesen in Sri Lanka mischt, wird's diffizil.

I would just say "residents of Singapore". Other words like Singaporean might be formally correct, but they are not familiar and not common.

On the other hand, I see that Google returns 3 million hits for "Singaporean" (http://www.google.com/search?q=%22singaporean...) so there are a lot of people who use it, but based on my own reaction as a native speaker of AE, the phrases "residents of Singapore" or "Singapore residents" seem more natural.

I strongly disagree with you, Eric. I can't see any reason why one should avoid "Singaporeans", and in most circumstances I would therefore avoid using "Singapore residents".

I don't think this is a US/UK difference - "Singaporeans" seems to show up quite frequently in the NY Times: http://query.nytimes.com/search/query?query=s...

Hab mal das Singapur-Kapitel eines englischsprachigen Südostasienreiseführers übersetzt.Da wurde durchgängig "Singaporeans" verwendet. Ich denke schon, dass die Bezeichnung gebräuchlich ist.

Auf Deutsch heißen sie übrigens Singapurer.