South Korean rapper Psy is using the royalties from his Gangnam Style mega hit to buy a house in Los Angeles.

The viral video star snapped up a $US1.25 million ($1.2 million) condominium in the exclusive Blair House building near Beverly Hills - and settled the big fee in cash, according to TMZ.

The cost of the two-bedroom pad is small change for the international chart sensation - he has reportedly raked in a whopping $US7.9 million in the past few months alone, just from the popularity of the catchy tune.

The song's promo, featuring his crazy horse-style dance routine, has become the most-watched video ever on YouTube after racking up more than 991 million views since July.