The company said that its flagship smartphone has surpassed the sales milestone some five months after arriving on the market.
"Meeting this sales milestone in five months sets another record for Samsung, and we are extremely proud yet motivated to provide our customers with products that they love," said Samsung IT and Mobile communications president JK Shin.
"On behalf of Samsung Mobile, I appreciate the millions of customers around the world that have chosen the Samsung Galaxy S3."
Since its release earlier this year, the Galaxy S3 has become a favourite amongst consumers and a lightning rod for controversy. While the handset has set sales record for Samsung and generated record profits, the handset has also been a target of patent infringement claims from rival Apple.
The Galaxy line itself has been at the centre of an ongoing legal battle between Apple and Samsung which has at various points threatened to halt imports of devices around the globe.
The 30 million sales mark also comes just two months after Samsung announced that the handset had topped 20 million sales, suggesting that that the smartphone is still fresh in the minds of consumers despite increased competition from the iPhone 5 and Windows Phone 8 handsets.