The original Galaxy S phone, launched in June 2010, sold 25 million units, the South Korean electronics giant said in a statement.
The Galaxy S II, launched in April 2011, racked up sales of more than 40 million, and the S III has reached the same volume since coming on the market in May last year.
For Samsung, 2012 was a watershed year that saw it take a giant bite out of Apple as it carved out a dominant position in the global mobile computing market.
Samsung saw its share of the lucrative smartphone market surge to 31.3 percent in the third quarter of 2012, up from just 3.3 percent in late 2009.
It extended its lead over Apple as the top maker of smartphones worldwide, according to research firm IHS iSuppli, which gave Samsung 28 percent of the market in 2012, up from 20 percent the previous year.
Apple's share rose to 20 percent in 2012 from 19 percent, IHS said.
The two tech giants have been embroiled in a long-running patent battle with each accusing the other of stealing designs and technology.
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