US research and consulting firm Strategy Analytics said the number of users topped one billion in the third quarter of 2012, with one out of every seven people worldwide carrying one of the devices.
The first smartphone, the Nokia Communicator, came out in 1996, but demand for the devices exploded after the release of Apple's iPhone in 2007.
"The iPhone revolutionized smartphone design and it catalyzed industry growth," Strategy Analytics Senior Analyst Scott Bicheno said in a statement.
"By the third quarter of 2011, we estimate there were 708 million smartphones in use worldwide. After a further year of soaring demand, the number of smartphones in use worldwide reached 1,038 billion units."
The research firm said it expected the number of users to double to two billion in less than three years.
"Smartphone penetration is still relatively low," Strategy Analytics Executive Director Neil Mawston said.
"Most of the world does not yet own a smartphone and there remains huge scope for future growth, particularly in emerging markets such as China, India and Africa."
Apple, which has sold more than five million of its latest iPhone 5 model since its release last month, nevertheless faces stiff competition from Samsung and other models powered by Google's Android software.
Get your daily dose of tech news, reviews, and insights, in under 80 characters on Gadgets 360 Turbo. Connect with fellow tech lovers on our Forum. Follow us on X, Facebook, WhatsApp, Threads and Google News for instant updates. Catch all the action on our YouTube channel.
Realme Will Try to Absorb Increased Cost of Components Ahead of Upcoming Product Launches, Executive Says
Motorola Edge 70 Launched With Snapdragon 7 Gen 4 Chipset, Slim 5.99mm Profile: Price, Specifications