The latest version of the company's tablet, which was unveiled this week, is set to hit shelves next Friday.
But tablets pre-ordered online will not ship to buyers until the following Monday, March 19, according to the company's website.
Earlier in the week, Apple had promised the newest tablet would arrive at customers' homes on the launch date.
Trudy Miller, an Apple spokeswoman, said the change was made because customer response to the new iPad had been "off the charts," quickly exhausting the supply set aside for pre-order and delivery by March 16.
Apple's new product releases are some of the hottest events on the tech calendar, scrutinized by investors, the media and industry insiders alike.
To the company's devoted fans, who vie to be the first to own the latest device, a three-day delay would be an eternity and could add to the crowds at the company's retail stores.
In January, enraged Chinese shoppers pelted Apple's flagship Beijing store with eggs and shoving matches broke out with police after customers were told the store would not begin sales of the iPhone 4S as scheduled.
The new iPad sports a crisper display and an array of technology advances and tweaks.
Apple said it will continue to sell the iPad 2 but dropped its price by $100. The older tablet now starts at $399 while the new third-generation wi-fi only iPad starts at $499.
The high-end model of Apple's latest iPad starts at $629 and will be capable of operating on a high-speed 4G "LTE," or Long-Term Evolution, network. At speeds roughly 10 times faster than current 3G technology, that may help banish the sometimes shaky video quality of older devices.