That's equivalent to the weight of 100 humpback whales.
Samsung launched the Galaxy S III in May and must be grinning from ear to ear with the sales it's experiencing.
Comparatively, the Galaxy S II sold just ten million units in 150 days.
JK Shin, president and head of IT & mobile communications division at Samsung, said: "The Galaxy S III continues to be a runaway favourite with customers around the world. Meeting this sales milestone in five months sets another record for Samsung, and we are extremely proud and yet motivated to continue to provide our customers with products that they love.
"On behalf of Samsung Mobile, I appreciate millions of customers around the world that have chosen the Samsung GALAXY S III."
In other news, the Galaxy Note II has hit sales of three million in one month – three times the rate of the original Note.
Check out the infographic below.