The Galaxy S3, unveiled in London earlier this month, will hit shelves Tuesday in nations including Britain, France and the United Arab Emirates, the firm said in a statement.
The phone will be available in 145 nations by July via 296 wireless carriers, it added.
The third version of the Galaxy S series offers face-recognition technology and improved voice-activated controls as well as a more powerful processor that lets users watch video and write emails simultaneously.
It also has a 4.8-inch (12.2-cm) screen that is 22 percent larger than the S2, while it can detect eye movements and override the automatic shutdown if the user is looking at the screen.
Samsung, the world's biggest technology firm, shipped 44.5 million smartphones in the first quarter, exceeding the 35.1 million of US rival Apple, according to market researcher Strategy Analytics last month.
It said the Korean firm also overtook Nokia as the biggest maker of all types of mobile phone in the same period.
Samsung is now pinning its hopes on the S3 to further erode its rivals' market share before the expected new version of Apple's iPhone 5 this year.
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