Apple sold a whopping four million iPhone 4S units in the three days after launch.
That's the highest first weekend sales ever for a phone.
More than 25 million customers are now using iOS 5, an upgraded mobile operating system.
"iPhone 4S is off to a great start with more than four million sold in its first weekend - the most ever for a phone and more than double the iPhone 4 launch during its first three days," said Apple's senior vice president of Worldwide Product Marketing Philip Schiller.
"iPhone 4S is a hit with customers around the world, and together with iOS 5 and iCloud, is the best iPhone ever."
One million pre-ordered the iPhone 4S in the 24 hours after it was announced.
It includes Apple's dual-core A5 chip, a new camera, 1080p HD video recording and Siri, a phone assistant that recognises voice commands.
The iPhone 4S went on sale at all 33 Apple shops in the UK at 8am on Friday, 14th October.