The smartphone will be on sale in the U.S. and Canada hours after its launch in Australia, Japan, Hong Kong, Singapore, Britain, France and Germany. It will launch in 22 more countries a week later. The iPhone 5 is thinner, lighter, has a taller screen, faster processor, updated software and can work on faster "fourth generation" mobile networks.
The handset has become a hot seller despite initial lukewarm reviews and new map software that is glitch prone. Apple received 2 million orders in the first 24 hours of announcing its release date, more than twice the number for the iPhone 4S in the same period when that phone launched a year ago.
Analysts have estimated Apple will ship as many as 10 million of the new iPhones by the end of September.
Some fans went to extremes to be among the first buyers by arriving at Apple's flagship stores day ahead of the release.